Clean up Gps/Flp Hardware on shut-down.

Ensures that the GPS and FLP HAL interfaces are deinitialized upon
system shut-down. This gives a chance for the underlying HAL to
close cleanly any resources it could be holding.
Note this approach only works for a device's power-off, scenarios
such as adb shell stop / start cannot  be handled, because in such
cases the process is terminated sending SIGKILL to it.

Bug: 23279835
Bug: 23279593
Change-Id: I29b3306c0ae2b384d0542031080a15fdbe49dd71