Merge branch 'hh/develop-pushblockcollab' of https://github.com/Unity-Technologies/ml-agents into hh/develop-pushblockcollab

Project/Assets/ML-Agents/Examples/Hallway/TFModels/HallwayCollab.onnx.meta

   fileIDToRecycleName:
     11400000: main obj
     11400002: model data
-    2186277476908879412: ImportLogs
   externalObjects: {}
   userData: 
   assetBundleName: 

Project/Assets/ML-Agents/Examples/PushBlock/Prefabs/PushBlockCollabArea.prefab

   m_Name: 
   m_EditorClassIdentifier: 
   m_BrainParameters:
-    VectorObservationSize: 0
+    VectorObservationSize: 1
     NumStackedVectorObservations: 2
     m_ActionSpec:
       m_NumContinuousActions: 0
     VectorActionSpaceType: 0
     hasUpgradedBrainParametersWithActionSpec: 1
-  m_Model: {fileID: 0}
+  m_Model: {fileID: 11400000, guid: c0cee535eae6c4b1e9a4c06ac84d4bcc, type: 3}
-  GroupId: 0
   m_UseChildSensors: 1
   m_UseChildActuators: 1
   m_ObservableAttributeHandling: 0
   m_Name: 
   m_EditorClassIdentifier: 
   m_BrainParameters:
-    VectorObservationSize: 0
+    VectorObservationSize: 1
     NumStackedVectorObservations: 2
     m_ActionSpec:
       m_NumContinuousActions: 0
     VectorActionSpaceType: 0
     hasUpgradedBrainParametersWithActionSpec: 1
-  m_Model: {fileID: 0}
+  m_Model: {fileID: 11400000, guid: c0cee535eae6c4b1e9a4c06ac84d4bcc, type: 3}
-  GroupId: 0
   m_UseChildSensors: 1
   m_UseChildActuators: 1
   m_ObservableAttributeHandling: 0

Project/Assets/ML-Agents/Examples/PushBlock/Scripts/PushAgentCollab.cs

             ForceMode.VelocityChange);
     }
 
-    // public override void CollectObservations(VectorSensor sensor)
-    // {
-    //     if (useVectorObs)
-    //     {
-    //         sensor.AddObservation(StepCount / (float)MaxStep);
-    //     }
-    // }
+    public override void CollectObservations(VectorSensor sensor)
+    {
+        if (useVectorObs)
+        {
+            sensor.AddObservation(StepCount / (float)MaxStep);
+        }
+    }
 
     /// <summary>
     /// Called every step of the engine. Here the agent takes an action.

Project/Packages/manifest.json

     "com.unity.ads": "2.0.8",
     "com.unity.analytics": "3.2.3",
     "com.unity.collab-proxy": "1.2.15",
-    "com.unity.ml-agents": "file:../../com.unity.ml-agents",
+    "com.unity.ml-agents": "1.7.0-preview",
     "com.unity.ml-agents.extensions": "file:../../com.unity.ml-agents.extensions",
     "com.unity.package-manager-ui": "2.0.8",
     "com.unity.purchasing": "2.0.3",