Return a runtime error instead of asserting if the AACDecoder is passed an unsupported config.

Change-Id: Ie084ed4df5a5d286abd36d9149c2138f8e7ed08a
related-to-bug: 2682221
QA-impact: none
diff --git a/media/libstagefright/AwesomePlayer.cpp b/media/libstagefright/AwesomePlayer.cpp
index 475160e..f668caa 100644
--- a/media/libstagefright/AwesomePlayer.cpp
+++ b/media/libstagefright/AwesomePlayer.cpp
@@ -778,7 +778,12 @@
             }
         }
 
-        mAudioSource->start();
+        status_t err = mAudioSource->start();
+
+        if (err != OK) {
+            mAudioSource.clear();
+            return err;
+        }
     } else if (!strcasecmp(mime, MEDIA_MIMETYPE_AUDIO_QCELP)) {
         // For legacy reasons we're simply going to ignore the absence
         // of an audio decoder for QCELP instead of aborting playback