[AWSMC-588] Support Bedrock log source

[ktmq]

What does this PR do?

Enables setting bedrock as the source tag for logs coming from s3 or Cloudwatch log groups

Motivation

Testing Guidelines

Tested by building the layer and using with a deployed Forwarder Lambda, configuring Model Invocation logs for both S3 and CloudWatch for Bedrock in the AWS account, and running some test model invocations to produce logs. Verified that both S3 and CloudWatch logs were received in the org with the source and service tags correctly set to bedrock.

Additional Notes

Types of changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

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• This PR contains breaking changes that are documented in the description
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