Fix NPE on clicking the all apps caret.

Change-Id: I2623e7470ffe711bce375699b9579803ded6c02f
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index f8b7c27..7423e20 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -2591,7 +2591,7 @@
     protected void onClickAllAppsButton(View v) {
         if (LOGD) Log.d(TAG, "onClickAllAppsButton");
         if (!isAppsViewVisible()) {
-            mUserEventDispatcher.logActionOnControl(LauncherLogProto.Action.TAP,
+            getUserEventDispatcher().logActionOnControl(LauncherLogProto.Action.TAP,
                     LauncherLogProto.ALL_APPS_BUTTON);
             showAppsView(true /* animated */, false /* resetListToTop */,
                     true /* updatePredictedApps */, false /* focusSearchBar */);
@@ -2601,7 +2601,7 @@
     protected void onLongClickAllAppsButton(View v) {
         if (LOGD) Log.d(TAG, "onLongClickAllAppsButton");
         if (!isAppsViewVisible()) {
-            mUserEventDispatcher.logActionOnControl(LauncherLogProto.Action.LONGPRESS,
+            getUserEventDispatcher().logActionOnControl(LauncherLogProto.Action.LONGPRESS,
                     LauncherLogProto.ALL_APPS_BUTTON);
             showAppsView(true /* animated */, false /* resetListToTop */,
                     true /* updatePredictedApps */, true /* focusSearchBar */);