White-list grandfathered sync adapters

Sync adapters were able to access the synced account without the accounts
permission which circumvents our permission model. Therefore, we require
sync adapters that don't have access to the account to get user consent.
This can be noisy, therefore we will white-list sync adapters installed
before we started checking for account access because they already know
the account (they run before) which is the genie is out of the bottle.

bug:31162498

Change-Id: I815e521778892ec592d53d086273743f1711bd17