How to Prevent System Font Size Changing to Android Mobile App Xamarin Forms

 Add Following Code in MainActivity.cs Page

AndroidProject/MainActivity.cs

 public override Resources Resources
 {
            get
            {
                Resources resource = base.Resources;
                Configuration configuration = new Configuration();
                configuration.SetToDefaults();
                if (Build.VERSION.SdkInt >= Android.OS.BuildVersionCodes.NMr1)
                {
                    return CreateConfigurationContext(configuration).Resources;
                }
                return resource;
            }
 }