Xamarin forms navigation bar scrolling on Android - xaml

Question

I have a simple File->New Project Xamarin Forms app just created. When the Editor gains focus the navigation bar slides up. Is this a bug, or how do you lock the navigation bar in place and scroll the page content instead?
Runnable source code can be download here. I am observing this behavior on a Samsung Note 3 phone. This doesn't happen in iOS.
https://github.com/JohnLivermore/SampleXamarinApp/tree/funkyNavbar
App.xaml
public partial class App : Application
{
public App()
{
InitializeComponent();
var mainPage = new MainPage();
var nav = new NavigationPage(mainPage);
MainPage = nav;
}
}
MainPage.xaml
<ContentPage 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"
Title="Page Title"
x:Class="SampleApp.MainPage">
<ScrollView>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Label Grid.Row="0" Text="Field A:" />
<Editor Grid.Row="1" HeightRequest="200" />
<Label Grid.Row="2" Text="Field B:" />
<Editor Grid.Row="3" HeightRequest="200" />
<Label Grid.Row="4" Text="Field B:" />
<Editor Grid.Row="5" HeightRequest="200" />
<Label Grid.Row="6" Text="Field B:" />
<Editor Grid.Row="7" HeightRequest="200" />
<Label Grid.Row="8" Text="Field B:" />
<Editor Grid.Row="9" HeightRequest="200" />
</Grid>
</ScrollView>
</ContentPage>

Answer 1

Add the following code in App.cs to make page auto-resizable.
using Xamarin.Forms.PlatformConfiguration.AndroidSpecific;
public partial class App : Xamarin.Forms.Application
{
public App()
{
Xamarin.Forms.Application.Current.On<Xamarin.Forms.PlatformConfiguration.Android>().UseWindowSoftInputModeAdjust(WindowSoftInputModeAdjust.Resize);
InitializeComponent();
MainPage = new NavigationPage(new MainPage());
}
}

Answer 2

If you want to make the toolbar's position static in Android, try adding this in [Activity] attribute in your MainActivity:
WindowSoftInputMode = Android.Views.SoftInput.AdjustNothing
More info here.