Use project/user from instance for quotas

If an admin confirms a resize, a periodic task auto-confirms a resize,
or if an admin reverts a resize, these should all use the instance
project/user for quota updates.

Closes-bug: 1271429
Closes-bug: 1278686
Closes-bug: 1278695

Change-Id: I1e128cd4035d0140e35582de795eb4d6fb8603f2
Merge "Use project/user from instance for quotas"