Fix Proguard (was stripping too much).

Bug: 2497870
Change-Id: I4ee61e9a02385bd43991bf22b73c0617ee6b9fae
diff --git a/proguard.flags b/proguard.flags
index 4c5ea69..ae1dddc 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -1,3 +1,4 @@
 -keepclassmembers class com.android.wallpaper.livepicker.LiveWallpaperPreview {
   public void setLiveWallpaper(android.view.View);
+  public void configureLiveWallpaper(android.view.View);
 }