[native] Update avatar hooks to support skipping keyserver upload
Summary:
Update avatar-hooks for uploading media to support a flag whether to upload metadata to keyserver. This bases on mechanism introduced in D13280
Depends on D13286
Test Plan: This is tested together with next diffs in the stack
Reviewers: kamil, tomek
Reviewed By: tomek
Subscribers: ashoat
Differential Revision: https://phab.comm.dev/D13294