Allow TouchControllers to override shouldDisableGestures

Currently only StatusBarTouchController overrides this to always return
false, so that you can swipe down for notifications during transition to
home screen from an app (in gesture nav).

Bug: 137161198
Change-Id: I803c37937d5294810cbe0c1bbffcd5dddcc5ca3b

quickstep/src/com/android/launcher3/uioverrides/touchcontrollers/StatusBarTouchController.java

@@ -166,4 +166,10 @@ public class StatusBarTouchController implements TouchController {
         mSysUiProxy = RecentsModel.INSTANCE.get(mLauncher).getSystemUiProxy();
         return mSysUiProxy != null;
     }
+
+    @Override
+    public boolean allowWhenGesturesDisabled() {
+        // Always allow intercepting touches for this controller.
+        return true;
+    }
 }