[Android] Suspend sync on all accounts

[sunjam]

Describe the feature you'd like to request

Ability to fully suspend all sync operations on all accounts within the app by a long press on the sync icon, or something similarly simple. Perhaps it makes the sync icon red to clarify all syncs are now suspended and must be resumed.

Describe the solution you'd like

Ability to fully suspend, or resume, sync operations with the click of a button.

This proves helpful if someone is referencing bookmarks and not trying to sync, regardless of how they've configured the client. Thanks for considering!

Describe alternatives you've considered

None. Related to #1129