Handle widget taps in WidgetPickerActivity.

Bug: 307306823
Test: atest Launcher3Tests
Flag: NA
Change-Id: I05cd42eae91447cfe99165096a735f6e04257203

src/com/android/launcher3/widget/WidgetCell.java

@@ -147,6 +147,11 @@ public class WidgetCell extends LinearLayout {
         return mAppWidgetHostViewScale;
     }
 
+    /** Returns the {@link WidgetItem} for this {@link WidgetCell}. */
+    public WidgetItem getWidgetItem() {
+        return mItem;
+    }
+
     /**
      * Called to clear the view and free attached resources. (e.g., {@link Bitmap}
      */