[Improvement] Manual sync progress

When the user presses on manual sync, a progress/loader should be displayed for the user and the button disabled in order to prevent multiple calls. The progress/loader should not block the UI though.
TBD: how and where should the progress/loader be displayed or if it's indefinite

Locate the manual sync action and its UI in the Android app, then clarify where the progress indicator should appear and whether it should be indeterminate. The work is done when manual sync shows non-blocking progress, disables the button to prevent duplicate calls, and restores the button after completion.

Written by the indexing model from the issue text.