Fix permission issue

Remove constant for READ_MEDIA_IMAGES permission.

Change-Id: I28f167c78a3abd5f70021b12c0ba477dac3e5d01
diff --git a/src/com/android/wallpaper/picker/WallpaperPickerDelegate.java b/src/com/android/wallpaper/picker/WallpaperPickerDelegate.java
index 6254d20..18a7c2c 100644
--- a/src/com/android/wallpaper/picker/WallpaperPickerDelegate.java
+++ b/src/com/android/wallpaper/picker/WallpaperPickerDelegate.java
@@ -79,8 +79,7 @@
     private PackageStatusNotifier.Listener mLiveWallpaperStatusListener;
     private PackageStatusNotifier.Listener mThirdPartyStatusListener;
     private CategoryProvider mCategoryProvider;
-    private static final String READ_PERMISSION = BuildCompat.isAtLeastQ() ?
-            permission.READ_MEDIA_IMAGES : permission.READ_EXTERNAL_STORAGE;
+    private static final String READ_PERMISSION = permission.READ_EXTERNAL_STORAGE;
 
     public WallpaperPickerDelegate(WallpapersUiContainer container, FragmentActivity activity,
             Injector injector) {