Make all modification operations serialized.

Prior to this change, it was possible for a profile operation and a
contacts operation to both be run simultaneously, since each DB
maintained a separate transaction lock.

With this change, ALL operations start a transaction on the contacts
DB, so modifications to either DB will be serialized.  This should
address the root cause of the jumbled mValues bugs, since only one
operation should be executing at any given time.

Bug 5248637

Change-Id: I4cdefddcb7b84f120d009300f45b772f439be88d
1 file changed