Add hardware.google.light@1.0-impl library

To allow including light HAL in a combined HAL server.

Bug: 135293492
Test: Check logcat for 'light'
Test: Check lshal for hardware.google.light@1.0
Test: Manually adjust display brightness
Test: All above tests without small_hals CL

Change-Id: I287aedaff3360707a50657c4c90748fe6e40b234