Bug:11064918 If the ContentResolver sync API is used with the empty ("") string as a provider, the ContentService will throw an RTE. This cl addresses all the entry points of the API that could allow this, as well as adds an ifEmpty check at the point of failure. Also removed RTE throws from public functions(no point in crashing the phone). Change-Id: I57427d12a6cafb3e6d7a32ca0c10b05315b20580