Use CustomizationPickerActivity as main activity

Screenshot: https://screenshot.googleplex.com/B76hYpdpftbooD4.png

Bug: 190354625
Test: m WallpaperPicker2
Change-Id: I04ca4ddb49d1cabc5e8e38a79be0e8043cd14c6d
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 5c2eeb5..5c020af 100755
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -61,18 +61,18 @@
          android:label="@string/app_name"
          android:theme="@style/WallpaperTheme.NoBackground"
          android:resizeableActivity="false"
-         android:exported="true">
-      <intent-filter>
-        <action android:name="android.intent.action.SET_WALLPAPER"/>
-        <category android:name="android.intent.category.DEFAULT"/>
-      </intent-filter>
+         android:exported="false">
     </activity>
 
     <activity android:name="com.android.wallpaper.picker.CustomizationPickerActivity"
         android:label="@string/app_name"
         android:resizeableActivity="false"
         android:theme="@style/WallpaperTheme.NoBackground"
-        android:exported="false">
+        android:exported="true">
+        <intent-filter>
+            <action android:name="android.intent.action.SET_WALLPAPER"/>
+            <category android:name="android.intent.category.DEFAULT"/>
+        </intent-filter>
     </activity>
 
     <activity android:name="com.android.wallpaper.picker.DeepLinkActivity"