Fix deprecation issue

permission_handler/ios/Classes/strategies/PhonePermissionStrategy.m

@@ -30,15 +30,30 @@
 }
 
 
-// https://stackoverflow.com/a/11595365
--(bool) canDevicePlaceAPhoneCall {
-    /*
-     * Returns YES if the device can place a phone call
+/**
+ * Returns YES if the device can place a phone call.
  */
-
-    // Device supports phone calls, lets confirm it can place one right now
+-(bool) canDevicePlaceAPhoneCall {
   CTTelephonyNetworkInfo *netInfo = [[CTTelephonyNetworkInfo alloc] init];
+  
+  if(@available(iOS 12.0, *)) {
+    NSDictionary<NSString *, CTCarrier *> *providers = [netInfo serviceSubscriberCellularProviders];
+    for (NSString *key in providers) {
+      CTCarrier *carrier = [providers objectForKey:key];
+      if ([self canPlacePhoneCallWithCarrier:carrier]) {
+        return YES;
+      }
+    }
+    
+    return NO;
+  } else {
     CTCarrier *carrier = [netInfo subscriberCellularProvider];
+    return [self canPlacePhoneCallWithCarrier:carrier];
+  }
+}
+
+-(bool)canPlacePhoneCallWithCarrier:(CTCarrier *)carrier {
+  // https://stackoverflow.com/a/11595365
   NSString *mnc = [carrier mobileNetworkCode];
   if (([mnc length] == 0) || ([mnc isEqualToString:@"65535"])) {
     // Device cannot place a call at this time.  SIM might be removed.