[Android] Fix issue updating the Label size changing the MaxLines (#11896) fixes #11875

* Added repro sample

* Fix the issue

Author: jsuarezruiz

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue11875.xaml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<controls:TestContentPage
+    xmlns:controls="clr-namespace:Xamarin.Forms.Controls"
+    xmlns="http://xamarin.com/schemas/2014/forms"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:d="http://xamarin.com/schemas/2014/forms/design"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    x:Class="Xamarin.Forms.Controls.Issues.Issue11875"
+    Title="Issue 11875">
+    <StackLayout>
+        <Label
+            Padding="12"
+            BackgroundColor="Black"
+            TextColor="White"
+            Text="If by increasing or decreasing the number of MaxLines, the Label size is adjusted correctly, the test has passed."/>
+        <Label
+            MaxLines="{Binding MaxLines}"
+            Text="Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum." />
+        <Label
+            FontSize="Micro"
+            Text="{Binding MaxLines}"/>
+        <Button
+            Command="{Binding IncreaseCommand}"
+            Text="Increase MaxLines"/>
+        <Button
+            Command="{Binding DecreaseCommand}"
+            Text="Decrease MaxLines"/>
+    </StackLayout>
+</controls:TestContentPage>

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue11875.xaml.cs

@@ -0,0 +1,73 @@
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+using Xamarin.Forms.Xaml;
+using System.Windows.Input;
+
+#if UITEST
+using Xamarin.UITest;
+using Xamarin.UITest.Queries;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+#if UITEST
+	[Category(UITestCategories.Label)]
+#endif
+#if APP
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+#endif
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 11875, "[Bug] Label MaxLine not updating value after changing from View Model",
+		PlatformAffected.Android)]
+	public partial class Issue11875 : TestContentPage
+	{
+		public Issue11875()
+		{
+#if APP
+			InitializeComponent();
+            BindingContext = new Issue11875ViewModel();
+#endif
+        }
+
+        protected override void Init()
+		{
+
+		}
+    }
+
+    public class Issue11875ViewModel : BindableObject
+    {
+        int _maxLines;
+
+        public Issue11875ViewModel()
+        {
+            MaxLines = 2;
+        }
+
+        public int MaxLines
+        {
+            get { return _maxLines; }
+            set
+            {
+                _maxLines = value;
+                OnPropertyChanged();
+            }
+        }
+
+        public ICommand IncreaseCommand => new Command(Increase);
+        public ICommand DecreaseCommand => new Command(Decrease);
+
+        void Increase()
+        {
+            MaxLines++;
+        }
+
+        void Decrease()
+        {
+            if (MaxLines > 0)
+                MaxLines--;
+        }
+    }
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -1484,6 +1484,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Issue11430.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11247.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue10608.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue11875.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11737.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11764.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11573.xaml.cs" />
@@ -1777,6 +1778,9 @@
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue11547.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue11875.xaml">
+     <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue11737.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>

Xamarin.Forms.Platform.Android/FastRenderers/LabelRenderer.cs

@@ -383,6 +383,7 @@ void UpdateLineBreakMode()
 		void UpdateMaxLines()
 		{
 			this.SetMaxLines(Element);
+			_lastSizeRequest = null;
 		}
 
 		void UpdateText()