chore: make the gapic code private

[Pulkit0110]

Changing the gapic directory from storage_v2 to _storage_v2 so that it acts as a private folder.

[chalmerlowe]

@Pulkit0110

I am curious:

• What are our reasons for suggesting this change to a private folder?
• Are there benefits to this that you see?
• Are there disadvantages to leaving the folder as is?

My understanding has always been that the folder names for all the GAPIC generated code are automatically created by the GAPIC generator and customarily use the format google/cloud/{packagename_v#}.

If that is the case, then changing the format here may not be a lasting change next time the GAPIC generated code gets rebuilt.

Relatedly, there are 60+ references to storage_v2 in this code base alone (especially in tests, etc). For example: from google.cloud import storage_v2

If the change to a new folder naming convention is approved, should those also be changed to _storage_v2?

Any insight you can offer is appreciated.

[danielduhh]

@chalmerlowe We're not exposing the gapic directly to customers -- thus moving this to a private folder makes sense. The plan is to write a veneer over the GAPIC client. See details here: go/storage-python-grpc & go/bidi-reads-py-sdk