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;
+                }
+            }
+        }
+    }
+}

src/App/Pages/Vault/CiphersPage.xaml

@@ -34,7 +34,7 @@
                     VerticalOptions="CenterAndExpand"
                     Clicked="BackButton_Clicked"
                     x:Name="_backButton" />
-                <SearchBar
+                <controls:ExtendedSearchBar
                     x:Name="_searchBar"
                     HorizontalOptions="FillAndExpand"
                     TextChanged="SearchBar_TextChanged"

src/App/Styles/Android.xaml

@@ -22,7 +22,8 @@
         <Setter Property="Margin"
                 Value="-4, 0, -4, -4" />
     </Style>
-    <Style TargetType="SearchBar">
+    <Style TargetType="SearchBar"
+           ApplyToDerivedTypes="True">
         <Setter Property="BackgroundColor"
                 Value="Transparent" />
         <Setter Property="TextColor"

src/App/Styles/iOS.xaml

@@ -35,7 +35,8 @@
         <Setter Property="OnColor"
                 Value="{StaticResource SwitchOnColor}" />
     </Style>
-    <Style TargetType="SearchBar">
+    <Style TargetType="SearchBar"
+           ApplyToDerivedTypes="True">
         <Setter Property="BackgroundColor"
                 Value="{StaticResource ListHeaderBackgroundColor}" />
         <Setter Property="TextColor"

src/iOS.Core/Services/DeviceActionService.cs

@@ -353,7 +353,15 @@ namespace Bit.iOS.Core.Services
 
         public bool UsingDarkTheme()
         {
-            return UIScreen.MainScreen.TraitCollection.UserInterfaceStyle == UIUserInterfaceStyle.Dark;
+            try
+            {
+                if(SystemMajorVersion() > 12)
+                {
+                    return UIScreen.MainScreen.TraitCollection.UserInterfaceStyle == UIUserInterfaceStyle.Dark;
+                }
+            }
+            catch { }
+            return false;
         }
 
         private void ImagePicker_FinishedPickingMedia(object sender, UIImagePickerMediaPickedEventArgs e)