b/12068020 Update calls to InputManager

This is part of work on making key layouts get saved per vendor/product
instead of per device. The corresponding change in fw is
https://googleplex-android-review.git.corp.google.com/#/c/399886/
This changes all uses of InputDevice descriptor to InputDeviceIdentifier.

Change-Id: I3eeebc0223820aeab62c2b8aa822f4d91adaf2d1