Defer starting the high-res thumbnail loader until quick step/scrub

- When hitting the home button, we may be loading high-res thumbnails
  unnecessarily since the high-res loader is already enabled when
  Launcher is started.

Bug: 111515602
Bug: 111156069

Change-Id: I367993b4ddf653b816355df005c745caed5e794a
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index c3c4f5e..4fe3503 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -348,6 +348,12 @@
     }
 
     @Override
+    public void onEnterAnimationComplete() {
+        super.onEnterAnimationComplete();
+        UiFactory.onEnterAnimationComplete(this);
+    }
+
+    @Override
     public void onConfigurationChanged(Configuration newConfig) {
         int diff = newConfig.diff(mOldConfig);
         if ((diff & (CONFIG_ORIENTATION | CONFIG_SCREEN_SIZE)) != 0) {