use black text for search bar on light theme

src/App/Controls/ExtendedSearchBar.cs

@@ -0,0 +1,21 @@
+using Bit.App.Abstractions;
+using Bit.Core.Utilities;
+using Xamarin.Forms;
+
+namespace Bit.App.Controls
+{
+    public class ExtendedSearchBar : SearchBar
+    {
+        public ExtendedSearchBar()
+        {
+            if(Device.RuntimePlatform == Device.iOS)
+            {
+                var deviceActionService = ServiceContainer.Resolve<IDeviceActionService>("deviceActionService", true);
+                if(!deviceActionService?.UsingDarkTheme() ?? false)
+                {
+                    TextColor = Color.Black;
+                }
+            }
+        }
+    }
+}