SyncManager should not allow syncing of data from apps that haven't opted
in to viewing restricted accounts in limited users.
Override getIsSyncable() to check if the sync adapter has the manifest
entry to enable restricted accounts of that account type. Return the default
isSyncable state if the adapter has opted in, otherwise return 0 for false.
Bug: 8566533
Change-Id: I3777f1e4fdb8debe1724ab083272e2d9bd2e63f2
This helps reduce the pressure on framework.jar, and makes it clear
that it should only be used by the system_server.
Bug: 7333397
Change-Id: I0858904239535380fbf30562b793e277d8c3f054
