camera_metadata: add lens facing EXTERNAL enum

This is for usb camera support

Change-Id: Id8329e31ad0622bdc06c60e87e97c742a9719b3b
4 files changed
tree: daf9f5982c3558c5db600e1a6491961a40478bc3
  1. audio_effects/
  2. audio_route/
  3. audio_utils/
  4. camera/
  5. private/
  6. CleanSpec.mk