Ensure media resumption controls have a title

This is a requirement stated in go/sysui-media-resumption-requirements
but was not actually being enforced.

Bug: 154823185
Test: manual
Change-Id: Iba10b37ff42733d8ef76faf14b90ed17877a1918

packages/SystemUI/src/com/android/systemui/qs/QSPanel.java

@@ -343,6 +343,11 @@ public class QSPanel extends LinearLayout implements Tunable, Callback, Brightne
                 return;
             }
 
+            if (desc == null || desc.getTitle() == null) {
+                Log.e(TAG, "Description incomplete");
+                return;
+            }
+
             Log.d(TAG, "adding track from browser: " + desc + ", " + component);
             QSMediaPlayer player = new QSMediaPlayer(mContext, QSPanel.this,
                     null, mForegroundExecutor, mBackgroundExecutor, mActivityStarter);