R2DBC in Cloud SQL : Enable support for IAM database authentication

[mpeddada1]

This seems to be blocked as described below:

Currently holding off on adding support for enabling IAM auth through the url as this doesn't seem to be working as expected for the R2DBC workflow. Extra options parsed from the url are automatically typed as String so when GcpConnectionFactoryProvider#createFactory in the Cloud SQL Java socket factory library calls (Boolean)connectionFactoryOptions.getValue(ENABLE_IAM_AUTH) this results in an error.

Originally posted by @mpeddada1 in #772 (comment)

[elefeint]

I think this will have to be a change in GcpConnectionFactoryProvider.
Even when the limitation in R2DBC gets addressed with some new API, the socket factory will still have to switch to using the new API.

[mpeddada1]

Thanks for the link to the limitation. Create an issue at GoogleCloudPlatform/cloud-sql-jdbc-socket-factory#686.