Merge "Removing BOARD_BUILD_SYSTEM_ROOT_IMAGE" am: 239ab9e265 am: cafddba4e8 am: 78b7d28908 am: c44d96b20d

Original change: https://android-review.googlesource.com/c/device/generic/common/+/2063543

Change-Id: Ib528f9c9ad3223f40bf461586b4944fe308a9eaf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>