Revert "Create a debugRoutingConfig param and a UnicornSecret (#290)" - see more details in descriptions

[jsy1218]

We revert, because the codepipeline beta-us-east-2 retry does not retrigger RoutingAPI.Prepare, which does not build CloudFormation resource anymore.

We did find the reason Codepipeline failed was due to:

User: arn:aws:sts::145079444317:assumed-role/cdk-hnb659fds-cfn-exec-role-145079444317-us-east-2/AWSCloudFormation is not authorized to perform: secretsmanager:GetSecretValue on resource: arn:aws:secretsmanager:us-east-2:644039819003:secret:debug-config-unicornsecrets-jvmCsq because no resource-based policy allows the secretsmanager:GetSecretValue action (Service: AWSSecretsManager; Status Code: 400; Error Code: AccessDeniedException; Request ID: 0b587919-9f34-46c7-a0da-0809f2dfc06c; Proxy: null)

But we added the policy to secrets afterwards (it seems like we always manually add policy to secrets instead of programmatically, since it's from cloudformation to secrets, not between stack to resource).

We don't believe there's any wrong with the change, so we will revert revert again.