When the mUri is null,it will happen NullPointerException.

When test the monkey, the mUri is existed to be null pointer high probability.

In order to prevent a null pointer exception, added a judgment condition that the mUri is not null or empty.

Test:Perform the monkey test,and See if this NullPointerException will happen again when call the method of android.media.Ringtone#play.

Bug: 169292270

Change-Id: I7907f0a376d67bb0a0f50ea155e2aa2f4552b1de

media/java/android/media/Ringtone.java

@@ -372,7 +372,7 @@ public class Ringtone {
                     AudioAttributes.toLegacyStreamType(mAudioAttributes)) != 0) {
                 startLocalPlayer();
             }
-        } else if (mAllowRemote && (mRemotePlayer != null)) {
+        } else if (mAllowRemote && (mRemotePlayer != null) && (mUri != null)) {
             final Uri canonicalUri = mUri.getCanonicalUri();
             final boolean looping;
             final float volume;