Define constants in IStreamListener in MediaKeys.h

Currently, constants in IStreamSource are being used in ATSParser while
they are separate entities. This defines those constants in MediaKeys.h
so that ATSParser can be used without depending on IStreamSource.

This removes libmedia dependency from libmpeg2extractor.

Test: build.
Bug: 67908537
Change-Id: I503a4cdb530825b1932463efae999d120b839e56
diff --git a/media/libmediaplayerservice/nuplayer/StreamingSource.cpp b/media/libmediaplayerservice/nuplayer/StreamingSource.cpp
index 388ca20..b3da53f 100644
--- a/media/libmediaplayerservice/nuplayer/StreamingSource.cpp
+++ b/media/libmediaplayerservice/nuplayer/StreamingSource.cpp
@@ -28,6 +28,7 @@
 #include <media/stagefright/foundation/ABuffer.h>
 #include <media/stagefright/foundation/ADebug.h>
 #include <media/stagefright/foundation/AMessage.h>
+#include <media/stagefright/foundation/MediaKeys.h>
 #include <media/stagefright/MetaData.h>
 #include <media/stagefright/Utils.h>
 
@@ -114,7 +115,7 @@
             int32_t mask;
             if (extra != NULL
                     && extra->findInt32(
-                        IStreamListener::kKeyDiscontinuityMask, &mask)) {
+                        kIStreamListenerKeyDiscontinuityMask, &mask)) {
                 if (mask == 0) {
                     ALOGE("Client specified an illegal discontinuity type.");
                     setError(ERROR_UNSUPPORTED);
@@ -142,7 +143,7 @@
                     int64_t mediaTimeUs;
                     memcpy(&mediaTimeUs, &buffer[2], sizeof(mediaTimeUs));
 
-                    extra->setInt64(IStreamListener::kKeyMediaTimeUs, mediaTimeUs);
+                    extra->setInt64(kATSParserKeyMediaTimeUs, mediaTimeUs);
                 }
 
                 mTSParser->signalDiscontinuity(