Add external camera support am: d66d2cfcf2 am: 7989f11cad am: 96fc5e5140

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

Change-Id: I7459f6e3fc4a5be002b62dc3afc76509bea06919