Rename camera compat utility methods in AppCompatActivityRobot.

It also makes many `AppCompatCameraPolicy` methods static, to avoid several
null checks when accesing camera compat classes via `ActivityRecord`
(`DisplayContent` could be null, and if it's not, all classes in the
`AppCompatCameraPolicy` could be null).

Flag: com.android.window.flags.enable_camera_compat_for_desktop_windowing
Bug: 370916718
Test: atest WmTests:AppCompatOrientationPolicyTest
Test: atest WmTests:AppCompatCameraPolicyTest
Change-Id: I3794b96df4ce77fa17be46b30c05f6bb38ae280c