AudioManager: permission annotations

Add permission annotations on audio focus @SystemApi methods.
Ignore REQUIRE_PERMISSION error (125) for:
 - deprecated abandonAudioFocus() method: the check is on the
    request call
 - isHdmiSystemAudioSupported() method, it's not clear if it's
    being used.

Test: remove "-hide 125" in Android.mk and make, verify no errors\
    on AudioManager.java
Bug: 62343127

Change-Id: I62526db0c6dabcc34224c589506d611519de6abc