Access incoming audio files after user taps Play

For platforms with insecure handling of media files, media files should
be opened only after the user chooses to play the media.

Change-Id: I5f9bbd1f8468a704a5962f0dddd3c8b11bba8bea

src/com/android/messaging/util/MediaUtil.java

@@ -33,4 +33,8 @@ public abstract class MediaUtil {
      */
     public abstract void playSound(final Context context, final int resId,
             final OnCompletionListener completionListener);
+
+    public static boolean canAutoAccessIncomingMedia() {
+        return OsUtil.isAtLeastM();
+    }
 }