adding retry to gcs client upload and download methods

[Anddraca]

Small update to make sure that the GCS storage client upload and download methods are using the Retry object defined on the class.

[brimoor]

nit: PR conventions:

• Add @voxel51/developers (or specific people, if appropriate) as reviewers
• Add yourself (or whoever should merge the PR once it is approved) as assignee
• Add appropriate labels to track type of work (for metrics, to guide reviewers on whether they are appropriate reviewers, etc)

[Anddraca]

Thanks for the points on setting up the PR -- I had assigned myself on a different issue but missed this one :grimacing:

As for the other methods: those do all take the retry object. I'll add those on if that's the desired behavior

[Anddraca]

Awesome. I did go through the other methods at this level, I think we're good for implementing retries for the GCS client