Merge "Merge "Revert "Normalize building generic system image with treble-common.mk"" into oc-dev am: 8199b9d1fd  -s ours am: db038f34f8" into oc-dr1-dev-plus-aosp
am: edc3e02d8a

Change-Id: Ic41047101ba7b517111bdb706d0d5e3001db455c