Fix wallpaper offset after boot

Bug: 10722164
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index 1818ade..09f37c4 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -1068,7 +1068,7 @@
 
     class WallpaperOffsetInterpolator implements Choreographer.FrameCallback {
         float mFinalOffset = 0.0f;
-        float mCurrentOffset = 0.0f;
+        float mCurrentOffset = 0.5f; // to force an initial update
         //long mLastWallpaperOffsetUpdateTime;
         boolean mWaitingForUpdate;
         Choreographer mChoreographer;