Add proxy methods to support invocation for inputstream/bytes

[xiwhuang]

What are we changing?

• Added two proxy methods to extend ResponseInputStream<AwsResponse> and ResponseBytes<AwsResponse>

Why are we changing?

• A few uncommon AWS APIs like S3::GetObject requires AWS Credentials Provider to authenticate the API requests

What happens if we do not change?

• Customers have to mimic a dummy request to extract out the credentials. for example, StackSet needs to validate the content in S3

How did we test?

• Manually tested the changes locally.
• Associated Unit tests pass.
• Create/Update/Delete succeed.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[wbingli]

Nice