Remove unnecessary flush() call in `TryToDecodeBase64Gzip` function

[dilyar85]

Please describe the solution you would like.
In https://github.com/vmware-tanzu/vm-operator/blob/main/pkg/util/enc.go, the TryToDecodeBase64Gzip function currently has a flush() call before close(). This flush() call seems unnecessary because the close() method will call flush() as well, as stated in https://pkg.go.dev/compress/gzip#Writer.Close.

Is there anything else you would like to add?
There are some test specs that use hardcoded strings to test this function. These test specs will also need to be updated when implementing the above change.

Please tell us about your environment.
N/A.

[akutz]

Just testing the new comment action.