Fix folder outline not matching the v28 radius.

Bug: 175329686
Test: manual, open folder and verify no visual artifacts
Change-Id: If7cfaf6f95e43ad6f2636b136bc98961554ebf36
diff --git a/src/com/android/launcher3/folder/FolderAnimationManager.java b/src/com/android/launcher3/folder/FolderAnimationManager.java
index feb528c..ee6ea99 100644
--- a/src/com/android/launcher3/folder/FolderAnimationManager.java
+++ b/src/com/android/launcher3/folder/FolderAnimationManager.java
@@ -40,7 +40,6 @@
 import com.android.launcher3.BubbleTextView;
 import com.android.launcher3.CellLayout;
 import com.android.launcher3.R;
-import com.android.launcher3.ResourceUtils;
 import com.android.launcher3.ShortcutAndWidgetContainer;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.anim.PropertyResetListener;
@@ -177,7 +176,7 @@
                 Math.round((totalOffsetX + initialSize)),
                 Math.round((paddingOffsetY + initialSize)));
         Rect endRect = new Rect(0, 0, lp.width, lp.height);
-        float finalRadius = ResourceUtils.pxFromDp(2, mContext.getResources().getDisplayMetrics());
+        float finalRadius = mFolderBackground.getCornerRadius();
 
         // Create the animators.
         AnimatorSet a = new AnimatorSet();