Fix NPE from NavbarButtonsViewController on FEATURE_PC devices.

When FEATURE_PC is enabled on a device,
DesktopNavbarButtonsViewController is instantiated. Previously,
DesktopNavbarButtonsViewController saves an internal copy of
mControllers and the mControllers field in NavbarButtonsViewController
is left unset. This was not a problem because mControllers in
NavbarButtonsViewController was not used in any code that was not
overridden by DesktopNavbarButtonsViewController.

ag/17944073 added some code that accesses mControllers in
NavbarButtonsViewController. Even though the code would be skipped for
FEATURE_PC devices (due to the TaskbarUIController check, which is
overridden by DesktopTaskbarUIController) in the end, it still caused an
NPE.

DesktopNavbarButtonsViewController does not require most of the button
updates done in NavbarButtonsViewController. Regardless, this CL
provides a workaround to avoid the NPE by setting mControllers in
NavbarButtonsViewController in FEATURE_PC devices.

Bug: 296623609
Bug: 297260211
Test: Manual; build and launch sdk_gpc emulator. Ensure that no crash
occurs

Change-Id: Ica22359b96fd0a277c575a238abb194d762e81ea
diff --git a/quickstep/src/com/android/launcher3/taskbar/DesktopNavbarButtonsViewController.java b/quickstep/src/com/android/launcher3/taskbar/DesktopNavbarButtonsViewController.java
index 885afff..29c5204 100644
--- a/quickstep/src/com/android/launcher3/taskbar/DesktopNavbarButtonsViewController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/DesktopNavbarButtonsViewController.java
@@ -18,6 +18,7 @@
 import static com.android.launcher3.taskbar.TaskbarNavButtonController.BUTTON_NOTIFICATIONS;
 import static com.android.launcher3.taskbar.TaskbarNavButtonController.BUTTON_QUICK_SETTINGS;
 
+import android.content.pm.ActivityInfo.Config;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -56,6 +57,11 @@
     @Override
     public void init(TaskbarControllers controllers) {
         mControllers = controllers;
+        super.init(controllers);
+    }
+
+    @Override
+    protected void setupController() {
         mNavButtonsView.getLayoutParams().height = mContext.getDeviceProfile().taskbarHeight;
 
         // Quick settings and notifications buttons
@@ -72,4 +78,7 @@
     /** Cleans up on destroy */
     @Override
     public void onDestroy() { }
+
+    @Override
+    public void onConfigurationChanged(@Config int configChanges) { }
 }
diff --git a/quickstep/src/com/android/launcher3/taskbar/NavbarButtonsViewController.java b/quickstep/src/com/android/launcher3/taskbar/NavbarButtonsViewController.java
index fcd8c80..fa16b61 100644
--- a/quickstep/src/com/android/launcher3/taskbar/NavbarButtonsViewController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/NavbarButtonsViewController.java
@@ -219,11 +219,15 @@
      */
     public void init(TaskbarControllers controllers) {
         mControllers = controllers;
+        setupController();
+    }
+
+    protected void setupController() {
         boolean isThreeButtonNav = mContext.isThreeButtonNav();
         DeviceProfile deviceProfile = mContext.getDeviceProfile();
         Resources resources = mContext.getResources();
         Point p = !mContext.isUserSetupComplete()
-                ? new Point(0, controllers.taskbarActivityContext.getSetupWindowHeight())
+                ? new Point(0, mControllers.taskbarActivityContext.getSetupWindowHeight())
                 : DimensionUtils.getTaskbarPhoneDimensions(deviceProfile, resources,
                         TaskbarManager.isPhoneMode(deviceProfile));
         mNavButtonsView.getLayoutParams().height = p.y;