[memory] Fix for tensors not being disposed of. (#2541)

* [memory] Fix for tensors not being disposed of.

* Fix member name.

UnitySDK/Assets/ML-Agents/Scripts/InferenceBrain/ApplierImpl.cs

                 {
                     actions[ii, actionIndex] = outputTensor.data[ii, 0];
                 }
+                actionProbs.data.Dispose();
+                outputTensor.data.Dispose();
             }
             var agentIndex = 0;
             foreach (var agent in agentInfo.Keys)

UnitySDK/Assets/ML-Agents/Scripts/InferenceBrain/GeneratorImpl.cs

 
         public void Generate(TensorProxy tensorProxy, int batchSize, Dictionary<Agent, AgentInfo> agentInfo)
         {
+            tensorProxy.data?.Dispose();
             tensorProxy.data = _allocator.Alloc(new TensorShape(1,1));
             tensorProxy.data[0] = batchSize;
         }
         public void Generate(TensorProxy tensorProxy, int batchSize, Dictionary<Agent, AgentInfo> agentInfo)
         {
             tensorProxy.shape = new long[0];
+            tensorProxy.data?.Dispose();
-
             tensorProxy.data[0] = 1;
         }
     }