Return early if extras for PermissionsActivity is null

* This should never happen as the SDK does send extras for this Activity, and no other entity should be creating PermissionsActivity.
* However, we have seen crash reports from our users that primarily seems to affect Nexus 5 and Pixel 3, in low numbers.
* One theory is that automatic testing done by the google play store is explicitly driving the PermissionsActivity.

Author: nan-li

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/activities/PermissionsActivity.kt

@@ -26,6 +26,11 @@ class PermissionsActivity : Activity() {
             return
         }
 
+        if (intent.extras == null) {
+            // This should never happen, but extras is null in rare crash reports
+            return
+        }
+
         requestPermissionService = OneSignal.getService()
         preferenceService = OneSignal.getService()