ios fixes

src/iOS.Core/Services/NoopDeviceActionService.cs

@@ -45,7 +45,7 @@ namespace Bit.iOS.Core.Services
 
         public Task<string> DisplayPromptAync(string title = null, string description = null, string text = null)
         {
-            // do nothing
+            return Task.FromResult<string>(null);
         }
 
         public void HideLoading()

src/iOS/Services/DeviceActionService.cs

@@ -341,6 +341,8 @@ namespace Bit.iOS.Services
                 input = x;
                 input.Text = text ?? string.Empty;
             });
+            var vc = GetPresentedViewController();
+            vc?.PresentViewController(alert, true, null);
             return result.Task;
         }