Only postpone animations if app is visible

Fixes bug where folders would remain open after
returning to launcher

Bug: 8681168

Change-Id: I930616f2aa006c1e23298dbdb0a80a9390ea41af
diff --git a/src/com/android/launcher2/Launcher.java b/src/com/android/launcher2/Launcher.java
index b20e3a5..fc42f3f 100644
--- a/src/com/android/launcher2/Launcher.java
+++ b/src/com/android/launcher2/Launcher.java
@@ -718,6 +718,18 @@
     }
 
     @Override
+    protected void onStop() {
+        super.onStop();
+        FirstFrameAnimatorHelper.setIsVisible(false);
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        FirstFrameAnimatorHelper.setIsVisible(true);
+    }
+
+    @Override
     protected void onResume() {
         super.onResume();