Deleting the WallpaperPicker code inside launcher.
Instead linking it to the packages/apps/WallpaperPicker project

Change-Id: Ib6830b180a22c22afece01e0a4f6e94e89d6452b
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index bce7120..418b1d2 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -93,7 +93,7 @@
 
         <activity
             android:name="com.android.launcher3.WallpaperPickerActivity"
-            android:theme="@style/Theme.WallpaperPicker"
+            android:theme="@style/WallpaperTheme.Picker"
             android:label="@string/pick_wallpaper"
             android:icon="@mipmap/ic_launcher_wallpaper"
             android:finishOnCloseSystemDialogs="true"
@@ -105,8 +105,8 @@
         </activity>
 
         <activity
-            android:name="com.android.launcher3.WallpaperCropActivity"
-            android:theme="@style/Theme.WallpaperCropper"
+            android:name="com.android.wallpaperpicker.WallpaperCropActivity"
+            android:theme="@style/WallpaperTheme"
             android:label="@string/crop_wallpaper"
             android:icon="@mipmap/ic_launcher_wallpaper"
             android:finishOnCloseSystemDialogs="true"