Update to 2019.2.0a8

Packages/manifest.json

     "com.unity.2d.sprite": "1.0.0",
     "com.unity.ads": "2.3.1",
     "com.unity.analytics": "3.2.2",
-    "com.unity.collab-proxy": "1.2.15",
+    "com.unity.collab-proxy": "1.2.16",
-    "com.unity.package-manager-ui": "2.1.2",
-    "com.unity.purchasing": "2.0.5",
+    "com.unity.package-manager-ui": "2.2.0",
+    "com.unity.purchasing": "2.0.6",
     "com.unity.textmeshpro": "1.3.0",
     "com.unity.timeline": "1.0.0",
     "com.unity.xr.arcore": "1.0.0-preview.24",

ProjectSettings/ProjectSettings.asset

   monoEnv: 
   splashScreenBackgroundSourceLandscape: {fileID: 0}
   splashScreenBackgroundSourcePortrait: {fileID: 0}
+  blurSplashScreenBackground: 1
   spritePackerPolicy: 
   webGLMemorySize: 256
   webGLExceptionSupport: 1

ProjectSettings/ProjectVersion.txt

-m_EditorVersion: 2019.2.0a7
-m_EditorVersionWithRevision: 2019.2.0a7 (8ab25c577b57)
+m_EditorVersion: 2019.2.0a8
+m_EditorVersionWithRevision: 2019.2.0a8 (18a4512f903f)

ProjectSettings/XRSettings.asset

+{
+    "m_SettingKeys": [
+        "VR Device Disabled",
+        "VR Device User Alert"
+    ],
+    "m_SettingValues": [
+        "False",
+        "False"
+    ]
+}