Grant set wallpaper dim amount permission to Wallpaper Picker (2/5)

Grant permission needed for the new WallpaperManager method
getWallpaperColors, to prepare for enabling color preview in the
multi-crop UI.

Flag: ACONFIG com.android.wallpaper.multi_crop_preview_ui_flag DEVELOPMENT
Bug: 315856338
Test: manually verified
Change-Id: I37f42df7fd374973ae95b106c37b324d52f213f7
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index b8126e5..de4737c 100755
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -15,6 +15,7 @@
     <uses-permission android:name="android.permission.READ_MEDIA_IMAGES"/>
     <uses-permission android:name="android.permission.READ_WALLPAPER_INTERNAL"/>
     <uses-permission android:name="android.permission.SET_WALLPAPER"/>
+    <uses-permission android:name="android.permission.SET_WALLPAPER_DIM_AMOUNT" />
 
     <queries>
         <package android:name="android"/>