Add NavigationModeFeatureFlag

3 Button mode doesn't use recents animation so live tile would not work on 3 button mode before migration to recents animation happens.

Bug: 169694902
Test: manual
Change-Id: I9574c624f3d220834fa18e910637cd64460adb0c

quickstep/src/com/android/quickstep/QuickstepProcessInitializer.java

@@ -15,6 +15,8 @@
  */
 package com.android.quickstep;
 
+import static com.android.quickstep.util.NavigationModeFeatureFlag.LIVE_TILE;
+
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.content.pm.PackageManager;
@@ -59,6 +61,8 @@ public class QuickstepProcessInitializer extends MainProcessInitializer {
 
         super.init(context);
 
+        LIVE_TILE.initialize(context);
+
         // Elevate GPU priority for Quickstep and Remote animations.
         ThreadedRendererCompat.setContextPriority(
                 ThreadedRendererCompat.EGL_CONTEXT_PRIORITY_HIGH_IMG);