Add external camera support am: d66d2cfcf2 am: a2ccd8ac06 am: 4187ba2cda

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

Change-Id: Ib685e0b5e03d3e66d303336f3f6e0365bdb036f8