Clarify PermissionStatus.restricted description.

Changing description from incorrect "user granted restricted access" to the description found on the Apple Developer site:
"kCLAuthorizationStatusRestricted
This app is not authorized to use location services.
The user cannot change this app’s status, possibly due to active restrictions such as parental controls being in place."
https://developer.apple.com/documentation/corelocation/clauthorizationstatus/kclauthorizationstatusrestricted

lib/src/permission_enums.dart

@@ -13,7 +13,9 @@ class PermissionStatus {
   /// Permission to access the requested feature is granted by the user.
   /// Permission to access the requested feature is granted by the user.
   static const PermissionStatus granted = PermissionStatus._(2);
   static const PermissionStatus granted = PermissionStatus._(2);
 
 
-  /// The user granted restricted access to the requested feature (only on iOS).
+  /// Permission to access the requested feature is denied by the OS (only on iOS).
+  /// The user cannot change this app's status, possibly due to active restrictions such as
+  /// parental controls being in place.
   static const PermissionStatus restricted = PermissionStatus._(3);
   static const PermissionStatus restricted = PermissionStatus._(3);
 
 
   /// Permission is in an unknown state
   /// Permission is in an unknown state