Merge "GenericSource: reset mDrmManagerClient when mDataSource is cleared." into mnc-dr-dev am: 7bfd9afefa am: 023815588c
am: 558f5c28c9

* commit '558f5c28c9a1e70dd9ef7ee2fbd33ef407a53de8':
  GenericSource: reset mDrmManagerClient when mDataSource is cleared.