Ensure that CommandQueue is a singleton.

Bug: 143844964
Test: atest SystemUITests && manual
Change-Id: Iec19cac45d2096107604d8d8eda80e45cf7f0170

packages/SystemUI/src/com/android/systemui/statusbar/StatusBarDependenciesModule.java

@@ -30,6 +30,7 @@ public class StatusBarDependenciesModule {
      * Provides our instance of CommandQueue which is considered optional.
      */
     @Provides
+    @Singleton
     public CommandQueue provideCommandQueue(Context context) {
         return new CommandQueue(context);
     }