Removes the A11y tutorial that displays on change to gesture navigation

Switching to gesture navigation puts button mode in FAB,
so there's no longer a need to show a gesture tutorial.

Test: change navigation modes. Verify no tutorial is shown for either option
Flag: android.provider.a11y_standalone_gesture_enabled
Bug: 371027085
Change-Id: I71e33efea3e25d22b0bc41c33b17de11f9ef2d64

src/com/android/settings/gestures/SystemNavigationGestureSettings.java

@@ -243,7 +243,9 @@ public class SystemNavigationGestureSettings extends RadioButtonPickerFragment i
     protected boolean setDefaultKey(String key) {
         setCurrentSystemNavigationMode(mOverlayManager, key);
         setIllustrationVideo(mVideoPreference, key);
-        setGestureNavigationTutorialDialog(key);
+        if (!android.provider.Flags.a11yStandaloneGestureEnabled()) {
+            setGestureNavigationTutorialDialog(key);
+        }
         setIllustrationClickListener(mVideoPreference, key);
         return true;
     }