env-vars-for-codebuild should support type of variable not just PLAINTEXT

[rohit-pdmi]

AWS Codebuild supports Environment Variable supports PLAINTEXT | PARAMETER_STORE | SECRETS_MANAGER as mentioned https://docs.aws.amazon.com/codebuild/latest/APIReference/API_EnvironmentVariable.html.

The github actions only supports PLAINTEXT. Support for PARAMETER_STORE | SECRETS_MANAGER should be added.