De-parent custom content view before adding to custom content screen

Bug: 11666352
Change-Id: Ief35e6e8a16ec0217e0dd27434723ee7a7d5beef
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index b1b50bf..02949e7 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -619,6 +619,12 @@
         if (customContent instanceof Insettable) {
             ((Insettable)customContent).setInsets(mInsets);
         }
+
+        // Verify that the child is removed from any existing parent.
+        if (customContent.getParent() instanceof ViewGroup) {
+            ViewGroup parent = (ViewGroup) customContent.getParent();
+            parent.removeView(customContent);
+        }
         customScreen.removeAllViews();
         customScreen.addViewToCellLayout(customContent, 0, 0, lp, true);
         mCustomContentDescription = description;