MultiHal 2.0 - activate, batch, flush methods of HalProxy

These three methods of HalProxy simply call the apropriate ISensors
methods of the subhal pointed to by sensorHandle.

Test: Loaded onto device and observed no crashing.
Bug: 136511617
Change-Id: If90652554ea18c22b24aead0074ab9847eae0a4f
1 file changed