base

Fix native calls to null pointer

Since DEVICE_AVAILABLE event fires right after initialization, it
could happen before TvInputHal.mPtr is set, which causes calls to
null pointer. Fix the bug by allowing TvInputHal to wait for mPtr to
be set before calling native methods.

Change-Id: Id07f15130beb69f77c16bf3c735285c31ae4a3a4