Infinite loop when migrating calendar widget

Second page can take y = 0

Fixes: 161201598
Test: manual
Change-Id: I6654db5c2c358dfb132268218dd044674e302e83
diff --git a/src/com/android/launcher3/model/GridSizeMigrationTaskV2.java b/src/com/android/launcher3/model/GridSizeMigrationTaskV2.java
index ebdfa8c..79467d3 100644
--- a/src/com/android/launcher3/model/GridSizeMigrationTaskV2.java
+++ b/src/com/android/launcher3/model/GridSizeMigrationTaskV2.java
@@ -406,7 +406,7 @@
          * to speed up the search.
          */
         private boolean findPlacement(DbEntry entry) {
-            for (int y = mNextStartY; y > 0; y--) {
+            for (int y = mNextStartY; y >= (mScreenId == 0 ? 1 /* smartspace */ : 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,