Revisit TypeNullableBool projection

[t0yv0]

The upstream provider defines a TypeNullableBool type that is represented as a Terraform string with values of "", "true", "false".

As of #4707 all instances of this type can be found here:

upstream/internal/service/ec2/ec2_launch_template.go:69:										Type:             nullable.TypeNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:71:										DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:72:										ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:75:										Type:             nullable.TypeNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:77:										DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:78:										ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:216:				Type:             nullable.TypeNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:218:				DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:219:				ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:746:							Type:             nullable.TypeNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:748:							DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:749:							ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:752:							Type:             nullable.TypeNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:754:							DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:755:							ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:758:							Type:             nullable.TypeNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:760:							DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:761:							ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:833:							Type:             nullable.TypeNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:835:							DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/ec2/ec2_launch_template.go:836:							ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/ec2/ec2_spot_fleet_request.go:844:				Type:         nullable.TypeNullableBool,
upstream/internal/service/ec2/ec2_spot_fleet_request.go:846:				ValidateFunc: nullable.ValidateTypeStringNullableBool,
upstream/internal/service/elasticache/replication_group.go:89:				Type:         nullable.TypeNullableBool,
upstream/internal/service/elasticache/replication_group.go:92:				ValidateFunc: nullable.ValidateTypeStringNullableBool,
upstream/internal/service/elasticache/cluster.go:68:				Type:         nullable.TypeNullableBool,
upstream/internal/service/elasticache/cluster.go:71:				ValidateFunc: nullable.ValidateTypeStringNullableBool,
upstream/internal/service/elasticache/replication_group_migrate.go:66:				Type:     nullable.TypeNullableBool,
upstream/internal/service/elbv2/target_group.go:211:				Type:             nullable.TypeNullableBool,
upstream/internal/service/elbv2/target_group.go:214:				DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/elbv2/target_group.go:215:				ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/mq/broker_data_source.go:181:							Type:     nullable.TypeNullableBool,
upstream/internal/service/mq/broker.go:260:							Type:             nullable.TypeNullableBool,
upstream/internal/service/mq/broker.go:262:							ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/mq/broker.go:263:							DiffSuppressFunc: nullable.DiffSuppressNullableBoolFalseAsNull,
upstream/internal/service/evidently/feature.go:166:										Type:         nullable.TypeNullableBool,
upstream/internal/service/evidently/feature.go:168:										ValidateFunc: nullable.ValidateTypeStringNullableBool,
upstream/internal/service/imagebuilder/container_recipe.go:146:													Type:             nullable.TypeNullableBool,
upstream/internal/service/imagebuilder/container_recipe.go:149:													DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/imagebuilder/container_recipe.go:150:													ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/imagebuilder/container_recipe.go:153:													Type:             nullable.TypeNullableBool,
upstream/internal/service/imagebuilder/container_recipe.go:156:													DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/imagebuilder/container_recipe.go:157:													ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/imagebuilder/image_recipe.go:68:										Type:             nullable.TypeNullableBool,
upstream/internal/service/imagebuilder/image_recipe.go:71:										DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/imagebuilder/image_recipe.go:72:										ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/imagebuilder/image_recipe.go:75:										Type:             nullable.TypeNullableBool,
upstream/internal/service/imagebuilder/image_recipe.go:78:										DiffSuppressFunc: nullable.DiffSuppressNullableBool,
upstream/internal/service/imagebuilder/image_recipe.go:79:										ValidateFunc:     nullable.ValidateTypeStringNullableBool,
upstream/internal/service/imagebuilder/image_recipe_data_source.go:47:										Type:     nullable.TypeNullableBool,
upstream/internal/service/imagebuilder/image_recipe_data_source.go:51:										Type:     nullable.TypeNullableBool,
upstream/internal/service/accessanalyzer/archive_rule.go:69:							Type:         nullable.TypeNullableBool,
upstream/internal/service/accessanalyzer/archive_rule.go:72:							ValidateFunc: nullable.ValidateTypeStringNullableBool,

By default this projects to Pulumi as "string", but in case of skipMetadataApiCheck property the Pulumi provider overrides the projection so that it projects as bool. We should consider if it is worth doing this in all the other places.