Use correct calling identity during camera permission check

UVC clients need to acquire the CAMERA permission
before trying to call open. The permission check is
currently done via calls to "checkCallingPermission".
In case the calling identity gets cleared, the check
will always fail. To resolve this, use "checkPermission"
with appropriate identity arguments.

Bug: 144433314
Test: Manual using application,
CtsVerifier USB Device test

Change-Id: I5318fbb4426bec1448ecc398c86ea96500bb3189