Handle permission-based admin policy persistence

Changes:
- Add a permission based admin to DevicePolicyData.
  This admin will not have a ComponentName or admin info.
- Update setCameraDisabled and getCameraDisabled to
  be callable by an app with the
  MANAGE_DEVICE_POLICY_CAMERA permission.

Bug: 234609037
Test: atest CameraPolicyTest
Change-Id: I5031c38f79c91fdccfae4ae3903e12016c6c83e4