Set smartspace to 30% visibility on workspace edit for home gardening

Here we set the smartspace to have 30% visibility to follow the guidelines set by https://docs.google.com/presentation/d/1FOmmCdmGmSMR77_901IOMbvbPVxPmjaAdxZjy-D9tw0/edit#slide=id.g159289e55db_0_229

Bug: 251259222
Test: Enter drag mode in workspace with SHOW_HOME_GARDENING flag on to see the changes
Change-Id: Ia2ef4f1a49549fef9f8fbea7c007db8b81972f71

src/com/android/launcher3/Workspace.java

@@ -919,6 +919,10 @@ public class Workspace<T extends View & PageIndicator> extends PagedView<T>
         return mScreenOrder;
     }
 
+    protected View getQsb() {
+        return mQsb;
+    }
+
     /**
      * Returns the screen ID of a page that is shown together with the given page screen ID when the
      * two panel UI is enabled.