Adding callback to notify LauncherCallbacks when quickstep starts

Bug: 73081875
Change-Id: Ieccba6ecb16553ed5211f277b49e9f2ed2d7c745
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 5da4944..5a1143fc 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -1193,6 +1193,12 @@
         }
     }
 
+    public void onQuickstepGestureStarted(boolean isVisible) {
+        if (mLauncherCallbacks != null) {
+            mLauncherCallbacks.onQuickstepGestureStarted(isVisible);
+        }
+    }
+
     public AllAppsTransitionController getAllAppsController() {
         return mAllAppsController;
     }