Update MRTK XR Rig.prefab

Author: keveleigh

org.mixedrealitytoolkit.input/Assets/Prefabs/MRTK XR Rig.prefab

@@ -220,7 +220,6 @@ MonoBehaviour:
       m_Action: Main Camera - TPD - Rotation
       m_Flags: 0
     m_Flags: 0
-  m_HasMigratedActions: 1
 --- !u!114 &404949538145338360
 MonoBehaviour:
   m_ObjectHideFlags: 0
@@ -238,15 +237,13 @@ MonoBehaviour:
     clearColor: {r: 0, g: 0, b: 0, a: 0}
     nearPlaneDistance: 0.1
     farPlaneDistance: 1000
-    adjustTrackingOrigin: 1
     adjustQualityLevel: 1
     qualityLevel: 5
   transparentDisplay:
     clearMode: 2
     clearColor: {r: 0, g: 0, b: 0, a: 0}
     nearPlaneDistance: 0.1
     farPlaneDistance: 50
-    adjustTrackingOrigin: 1
     adjustQualityLevel: 1
     qualityLevel: 0
 --- !u!1 &2351505566903569413

org.mixedrealitytoolkit.input/CHANGELOG.md

@@ -4,6 +4,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## Unreleased
 
+### Changed
+
+* Reserialized MRTK XR Rig prefab to remove stale serialized fields. [PR #1110](https://github.com/MixedRealityToolkit/MixedRealityToolkit-Unity/pull/1110)
+
 ### Fixed
 
 * Fixed `EyeCalibrationChecker` build issue on UWP when the Mixed Reality OpenXR Plugin wasn't installed. [PR #1106](https://github.com/MixedRealityToolkit/MixedRealityToolkit-Unity/pull/1106)