MediaCas: add framework APIs

Java API changes to support MediaCas framework.

Also add partial-frame related enums to MediaCodec,
MediaCodecInfo, and MediaExtractor as a way to indicate
a input frame contains partial data.

Test: basic test app and test plugin to execise the code path;
impelenting playback of CAS-secured MPEG2TS streams, including
a Widevine-based CAS plugin, locally modified ExoPlayer and
Android TV Tuner input.

bug: 22804304
Change-Id: Ia4ba1d4046f7588e42bfb21e726390457d2fc8e3
diff --git a/Android.mk b/Android.mk
index b98d3bc..0cf74b8 100644
--- a/Android.mk
+++ b/Android.mk
@@ -409,6 +409,10 @@
 	location/java/android/location/INetInitiatedListener.aidl \
 	location/java/com/android/internal/location/ILocationProvider.aidl \
 	media/java/android/media/IAudioService.aidl \
+	media/java/android/media/ICas.aidl \
+	media/java/android/media/ICasListener.aidl \
+	media/java/android/media/IDescrambler.aidl \
+	media/java/android/media/IMediaCasService.aidl \
 	media/java/android/media/IAudioFocusDispatcher.aidl \
 	media/java/android/media/IAudioRoutesObserver.aidl \
 	media/java/android/media/IMediaHTTPConnection.aidl \