Remove mesh colliders from soccer scenes (#4949)

Project/Assets/ML-Agents/Examples/Soccer/Scenes/SoccerTwos.unity

   m_Modification:
     m_TransformParent: {fileID: 0}
     m_Modifications:
+    - target: {fileID: 1141134673700168, guid: 54f3340298537426e96a6cc530e2d5d8, type: 3}
+      propertyPath: m_Name
+      value: SoccerFieldTwos
+      objectReference: {fileID: 0}
     - target: {fileID: 4558743310993102, guid: 54f3340298537426e96a6cc530e2d5d8, type: 3}
       propertyPath: m_LocalPosition.x
       value: 0
     - target: {fileID: 4558743310993102, guid: 54f3340298537426e96a6cc530e2d5d8, type: 3}
       propertyPath: m_RootOrder
       value: 4
+      objectReference: {fileID: 0}
+    - target: {fileID: 4558743310993102, guid: 54f3340298537426e96a6cc530e2d5d8, type: 3}
+      propertyPath: m_LocalEulerAnglesHint.x
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: 4558743310993102, guid: 54f3340298537426e96a6cc530e2d5d8, type: 3}
+      propertyPath: m_LocalEulerAnglesHint.y
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: 4558743310993102, guid: 54f3340298537426e96a6cc530e2d5d8, type: 3}
+      propertyPath: m_LocalEulerAnglesHint.z
+      value: 0
       objectReference: {fileID: 0}
     m_RemovedComponents: []
   m_SourcePrefab: {fileID: 100100000, guid: 54f3340298537426e96a6cc530e2d5d8, type: 3}
   m_Name: 
   m_EditorClassIdentifier: 
   gravityMultiplier: 1
-  monitorVerticalOffset: 0
+  reuseCollisionCallbacks: 1
 --- !u!114 &1574236051
 MonoBehaviour:
   m_ObjectHideFlags: 0
   blueMaterial: {fileID: 2100000, guid: c9fa44c2c3f8ce74ca39a3355ea42631, type: 2}
   randomizePlayersTeamForTraining: 0
   agentRunSpeed: 2
-  strikerPunish: -0.1
-  strikerReward: 1
-  goaliePunish: -1
-  goalieReward: 0.1
 --- !u!1001 &1606160104
 PrefabInstance:
   m_ObjectHideFlags: 0

Project/Assets/ML-Agents/Examples/Soccer/Scenes/StrikersVsGoalie.unity

   maximumDeltaTime: 0.33333334
   solverIterations: 6
   solverVelocityIterations: 1
+  reuseCollisionCallbacks: 1
 --- !u!114 &1574236051
 MonoBehaviour:
   m_ObjectHideFlags: 0