updated to the lastest AR Foundation packages

Packages/manifest.json

     "com.unity.textmeshpro": "2.0.1",
     "com.unity.timeline": "1.2.10",
     "com.unity.ugui": "1.0.0",
-    "com.unity.xr.arcore": "3.1.0-preview.4",
-    "com.unity.xr.arfoundation": "3.1.0-preview.4",
-    "com.unity.xr.arkit": "3.1.0-preview.4",
+    "com.unity.xr.arcore": "3.1.0-preview.8",
+    "com.unity.xr.arfoundation": "3.1.0-preview.8",
+    "com.unity.xr.arkit": "3.1.0-preview.8",
     "com.unity.xr.legacyinputhelpers": "1.3.8",
     "com.unity.modules.ai": "1.0.0",
     "com.unity.modules.androidjni": "1.0.0",

ProjectSettings/ProjectSettings.asset

   bundleVersion: 0.1
   preloadedAssets:
   - {fileID: 4800000, guid: c9f956787b1d945e7b36e0516201fc76, type: 3}
-  - {fileID: 4800000, guid: e7c77f6eaab324a819efdc13b8125a39, type: 3}
   metroInputSource: 0
   wsaTransparentSwapchain: 0
   m_HolographicPauseOnTrackingLoss: 1