MH2 | Write processedEvents instead of original events.

Fix bug where the HalProxyCallback::postEvents method was passing the
unaltered events vector to HalProxy::postEventsToMessageQueue instead of
the processedEvents with altered sensorHandles. Add a unit test to test
that the proper sensorHandles are seen compared to the event posted from
subhal.

Additionally, fix problems with fake subhals and their dummy sensors
that allows VTS tests to pass all tests.

Bug: 136511617
Test: New unit tests pass and VTS tests under module
VtsHalSensorsV2_0Target passing.
Change-Id: If30da03a2399666700844523cd1104b07f6b65d2