Add external camera support am: d66d2cfcf2 am: a2ccd8ac06 am: 1a1c150381

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Camera2/+/11604391

Change-Id: I0884ab9e43bcf9f95cb4ea391ce30323a50dd5cc