Update slots to support assigning to specific items

Assets/Prefabs/Items/BlueBall.prefab

@@ -57,6 +57,7 @@ BoxCollider:
   m_Center: {x: 0, y: 0, z: 0}
 --- !u!212 &4774534086162962138
 SpriteRenderer:
+  serializedVersion: 2
   m_ObjectHideFlags: 0
   m_CorrespondingSourceObject: {fileID: 0}
   m_PrefabInstance: {fileID: 0}
@@ -102,6 +103,7 @@ SpriteRenderer:
   m_SortingLayerID: 0
   m_SortingLayer: 0
   m_SortingOrder: 1
+  m_MaskInteraction: 0
   m_Sprite: {fileID: 4799961156935096247, guid: 74289c1614ce2b2439a5d3ff60a90d66, type: 3}
   m_Color: {r: 1, g: 1, b: 1, a: 1}
   m_FlipX: 0
@@ -111,7 +113,6 @@ SpriteRenderer:
   m_AdaptiveModeThreshold: 0.5
   m_SpriteTileMode: 0
   m_WasSpriteAssigned: 1
-  m_MaskInteraction: 0
   m_SpriteSortPoint: 1
 --- !u!114 &5483561632297398438
 MonoBehaviour: