Fixed the picker title's color (#23075)

* Fixed the picker title's color (#16737)

* Added a test category

* Enable test on all platforms

Author: kubaflo

src/Controls/tests/TestCases.HostApp/Issues/Issues16737.xaml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue16737">
+    <VerticalStackLayout>
+        <Label AutomationId="label"
+                Text="Picker test"/>
+        <Picker
+            Title="Select something"
+            TitleColor="Red"
+            TextColor="Red">
+            <Picker.ItemsSource>
+                <x:Array Type="{x:Type x:String}">
+                    <x:String>Maui</x:String>
+                    <x:String>Maui</x:String>
+                </x:Array>
+            </Picker.ItemsSource>
+        </Picker>
+    </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issues16737.xaml.cs

@@ -0,0 +1,15 @@
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 16737, "Title colour on Android Picker, initially appears grey", PlatformAffected.All)]
+	public partial class Issue16737 : ContentPage
+	{
+		public Issue16737()
+		{
+			InitializeComponent();
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue16737.cs

@@ -0,0 +1,24 @@
+using NUnit.Framework;
+using NUnit.Framework.Legacy;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue16737 : _IssuesUITest
+	{
+		public Issue16737(TestDevice device) : base(device) { }
+
+		public override string Issue => "Title colour on Android Picker, initially appears grey";
+
+		[Test]
+		[Category(UITestCategories.Picker)]
+		public void Issue16737Test()
+		{
+			_ = App.WaitForElement("label");
+
+			// The test passes if the title's color is red
+			VerifyScreenshot();
+		}
+	}
+}

src/Core/src/Platform/Android/PickerExtensions.cs

@@ -16,6 +16,8 @@ public static void UpdateTitleColor(this MauiPicker platformPicker, IPicker pick
 			{
 				if (PlatformInterop.CreateEditTextColorStateList(platformPicker.TextColors, titleColor.ToPlatform()) is ColorStateList c)
 					platformPicker.SetHintTextColor(c);
+				else if(picker.TextColor == picker.TitleColor)
+					platformPicker.SetHintTextColor(titleColor.ToPlatform());
 			}
 		}