Removed unnecessary packages from manifest in order to avoid issues with them when Unity upgrades the projects across Unity versions.

https://jira.unity3d.com/browse/XRE-3424

Packages/manifest.json

 {
   "dependencies": {
-    "com.unity.2d.sprite": "1.0.0",
-    "com.unity.2d.tilemap": "1.0.0",
-    "com.unity.analytics": "3.3.5",
-    "com.unity.collab-proxy": "1.3.9",
-    "com.unity.ext.nunit": "1.0.0",
-    "com.unity.purchasing": "2.1.1",
-    "com.unity.test-framework": "1.1.18",
-    "com.unity.textmeshpro": "3.0.1",
-    "com.unity.ugui": "1.0.0",
     "com.unity.xr.arcore": "4.1.0-preview.10",
     "com.unity.xr.arfoundation": "4.1.0-preview.10",
     "com.unity.xr.arkit": "4.1.0-preview.10",

ProjectSettings/ProjectVersion.txt

-m_EditorVersion: 2020.1.8f1
-m_EditorVersionWithRevision: 2020.1.8f1 (22e8c0b0c3ec)
+m_EditorVersion: 2019.4.9f1
+m_EditorVersionWithRevision: 2019.4.9f1 (50fe8a171dd9)