Remove use of private APIs

Change-Id: I3e28763075f8e92391796dc009214c9fa8f50008
diff --git a/src/com/android/launcher2/IconCache.java b/src/com/android/launcher2/IconCache.java
index efa9fac..1e42f1b 100644
--- a/src/com/android/launcher2/IconCache.java
+++ b/src/com/android/launcher2/IconCache.java
@@ -64,7 +64,7 @@
 
     public Drawable getFullResDefaultActivityIcon() {
         return getFullResIcon(Resources.getSystem(),
-                com.android.internal.R.mipmap.sym_def_app_icon);
+                android.R.mipmap.sym_def_app_icon);
     }
 
     public Drawable getFullResIcon(Resources resources, int iconId) {