Workspace migration should start from CellY = 1

Test: Manual
Fixes: 155828336
Change-Id: Ic262f63e5e9dc0a5738f71a84dc5cc8b0cefd321
diff --git a/src/com/android/launcher3/model/GridSizeMigrationTaskV2.java b/src/com/android/launcher3/model/GridSizeMigrationTaskV2.java
index a5d798b..5ba2c8e 100644
--- a/src/com/android/launcher3/model/GridSizeMigrationTaskV2.java
+++ b/src/com/android/launcher3/model/GridSizeMigrationTaskV2.java
@@ -384,7 +384,7 @@
          * to speed up the search.
          */
         private boolean findPlacement(DbEntry entry) {
-            for (int y = mNextStartY; y >= 0; y--) {
+            for (int y = mNextStartY; y > 0; y--) {
                 for (int x = mNextStartX; x < mTrgX; x++) {
                     boolean fits = mOccupied.isRegionVacant(x, y, entry.spanX, entry.spanY);
                     boolean minFits = mOccupied.isRegionVacant(x, y, entry.minSpanX,