added mouse input manager back in registered service provider list

Author: StephenHodgson

Assets/MixedRealityToolkit-SDK/Profiles/DefaultMixedRealityRegisteredServiceProvidersProfile.asset

@@ -62,3 +62,10 @@ MonoBehaviour:
     priority: 10
     runtimePlatform: 8
     configurationProfile: {fileID: 0}
+  - componentType:
+      reference: Microsoft.MixedReality.Toolkit.Core.Devices.UnityInput.MouseDeviceManager,
+        Microsoft.MixedReality.Toolkit
+    componentName: Mouse Input Manager
+    priority: 10
+    runtimePlatform: -1
+    configurationProfile: {fileID: 0}