[Testing] Added UI Test for manual test D9 (dotnet#18762)

* Added UI Test

* Updated test

* Changes to ensure other tests

* Revert changes

* Updated test

src/Controls/samples/Controls.Sample.UITests/Issues/Issue18754.xaml

@@ -0,0 +1,26 @@
+<?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.Issue18754">
+    <ScrollView>
+        <VerticalStackLayout>
+            <Label
+                AutomationId="WaitForStubControl"
+                Text="1. Attempt to enter any text into the editor below." />
+            <Label 
+                Text="2. The test fails if the editor displays the input." />
+            <Editor
+                AutomationId="ReadOnlyEditor"
+                IsReadOnly="True" 
+                Text="" />
+            <Label 
+                Text="3. Attempt to edit the text in the editor below." />
+            <Label
+                Text="4. The test fails if the editor displays the input." />
+            <Editor
+                AutomationId="FilledReadOnlyEditor"
+                IsReadOnly="True"
+                Text="Try to edit this." />
+        </VerticalStackLayout>
+    </ScrollView>
+</ContentPage>

src/Controls/samples/Controls.Sample.UITests/Issues/Issue18754.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.ManualTest, "D9", "[D9] Editor IsReadOnly works", PlatformAffected.All)]
+	public partial class Issue18754 : ContentPage
+	{
+		public Issue18754()
+		{
+			InitializeComponent();
+		}
+	}
+}

src/Controls/tests/UITests/Tests/Issues/Issue18675.cs

@@ -13,13 +13,17 @@ public Issue186751(TestDevice device) : base(device)
 		public override string Issue => "Editor IsReadOnly property prevent from modifying the text";
 
 		[Test]
-		public void EditorIsReadOnlyPreventModify()
+		public async Task EditorIsReadOnlyPreventModify()
 		{
 			App.WaitForElement("WaitForStubControl");
 
 			// 1.The test fails if the placeholder text in the editor below is missing.
 			App.Click("IsReadOnlyEditor");
 
+			// Delay for the Editor underline on Android to return from
+			// the selected state to normal state.
+			await Task.Delay(500);
+
 			// 2. The test fails if the placeholder text in the editor below is not blue.
 			VerifyScreenshot();
 		}

src/Controls/tests/UITests/Tests/Issues/Issue18754.cs

@@ -0,0 +1,34 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.AppiumTests.Issues
+{
+	public class Issue18754 : _IssuesUITest
+	{
+		public Issue18754(TestDevice device) : base(device) { }
+
+		public override string Issue => "[D9] Editor IsReadOnly works";
+
+		[Test]
+		public void Issue18754Test()
+		{
+			this.IgnoreIfPlatforms(new TestDevice[] { TestDevice.Mac, TestDevice.Windows },
+				"Currently IsKeyboardShown is not implemented.");
+
+			App.WaitForElement("WaitForStubControl");
+
+			// 1. Attempt to enter any text into the editor below.
+			App.Click("ReadOnlyEditor");
+
+			// 2. The test fails if the editor displays the input.
+			Assert.IsFalse(App.IsKeyboardShown());
+
+			// 3. Attempt to edit the text in the editor below.
+			App.Click("FilledReadOnlyEditor");
+
+			// 4. The test fails if the editor displays the input.
+			Assert.IsFalse(App.IsKeyboardShown());
+		}
+	}
+}