Update camera clear flags to solid color

Author: hj-cpdm-son

Samples~/XRController/XRControllerSample.unity

@@ -155,8 +155,8 @@ Camera:
   m_GameObject: {fileID: 330585543}
   m_Enabled: 1
   serializedVersion: 2
-  m_ClearFlags: 1
-  m_BackGroundColor: {r: 0.19215687, g: 0.3019608, b: 0.4745098, a: 0}
+  m_ClearFlags: 2
+  m_BackGroundColor: {r: 0, g: 0, b: 0, a: 0}
   m_projectionMatrixMode: 1
   m_GateFitMode: 2
   m_FOVAxisMode: 0
@@ -182,7 +182,7 @@ Camera:
   field of view: 60
   orthographic: 0
   orthographic size: 5
-  m_Depth: -1
+  m_Depth: 0
   m_CullingMask:
     serializedVersion: 2
     m_Bits: 4294967295