Implement the bottom action bar for the wallpaper section.

- Implement the container of the bottom action bar.
- Add Cancel and Rotation action items.

Screenshot:
https://screenshot.googleplex.com/TaBigRfTnnA.png

Bug: 150103722
Change-Id: Ic004339c681d85743e003ecc4092e591e4cdc76f
diff --git a/src/com/android/wallpaper/picker/TopLevelPickerActivity.java b/src/com/android/wallpaper/picker/TopLevelPickerActivity.java
index 8dbeabb..e15b2f1 100755
--- a/src/com/android/wallpaper/picker/TopLevelPickerActivity.java
+++ b/src/com/android/wallpaper/picker/TopLevelPickerActivity.java
@@ -168,7 +168,7 @@
 
         @WallpaperSupportLevel int wallpaperSupportLevel = mDelegate.getWallpaperSupportLevel();
         if (wallpaperSupportLevel != WallpaperDisabledFragment.SUPPORTED_CAN_SET) {
-            setContentView(R.layout.activity_single_fragment);
+            setContentView(R.layout.activity_top_level_picker);
 
             FragmentManager fm = getSupportFragmentManager();
             WallpaperDisabledFragment wallpaperDisabledFragment =
@@ -252,7 +252,7 @@
     }
 
     private void initializeMobile(boolean shouldForceRefresh) {
-        setContentView(R.layout.activity_single_fragment);
+        setContentView(R.layout.activity_top_level_picker);
         getWindow().getDecorView().setSystemUiVisibility(
                 getWindow().getDecorView().getSystemUiVisibility()
                         | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION