Ignore setWallpaperColors method when not using WallpaperColors

Bug: 186874050
Test: manual
Change-Id: Id3c6f039cfd18d487f948ffb9912e56f264c10b6
diff --git a/src/com/android/wallpaper/picker/ImagePreviewFragment.java b/src/com/android/wallpaper/picker/ImagePreviewFragment.java
index 313d215..4e0b54a 100755
--- a/src/com/android/wallpaper/picker/ImagePreviewFragment.java
+++ b/src/com/android/wallpaper/picker/ImagePreviewFragment.java
@@ -98,12 +98,12 @@
     private ImageView mLowResImageView;
     private TouchForwardingLayout mTouchForwardingLayout;
     private ConstraintLayout mContainer;
-    private SurfaceView mWorkspaceSurface;
     private SurfaceView mWallpaperSurface;
     private WallpaperInfoView mWallpaperInfoView;
     private Optional<Integer> mLastSelectedTabPositionOptional = Optional.empty();
     private AtomicInteger mImageScaleChangeCounter = new AtomicInteger(0);
 
+    protected SurfaceView mWorkspaceSurface;
     protected WorkspaceSurfaceHolderCallback mWorkspaceSurfaceCallback;
     protected ViewGroup mLockPreviewContainer;
     protected LockScreenPreviewer2 mLockScreenPreviewer;