[Shell,Android] NavigationBar items not styling as expected

[davidortinau]

Description

I don't get a text label on Android for the left item (BackButtonBehavior) like I do on iOS.

The "blanky" drawable is an empty shape just so Shell doesn't crash. See #5211

The right ToolBarItem is white and should be orange. Shell seems to be using a different property to map here.

<Shell.Resources>
        <ResourceDictionary>
            <Color x:Key="NavigationPrimary">#f3f3f3</Color>
            <Color x:Key="ActionColor">#f05123</Color>
            <Color x:Key="LightGray">#f05123</Color>
            <Color x:Key="DarkGray">#383332</Color>
            <Style x:Key="BaseStyle" TargetType="Element">
                <Setter Property="Shell.ShellBackgroundColor" Value="{StaticResource NavigationPrimary}" />
                <Setter Property="Shell.ShellForegroundColor" Value="{StaticResource ActionColor}" />
                <Setter Property="Shell.ShellTitleColor" Value="{StaticResource DarkGray}" />
                <Setter Property="Shell.ShellDisabledColor" Value="#B4FFFFFF" />
                
                <Setter Property="Shell.ShellTabBarBackgroundColor" Value="{StaticResource NavigationPrimary}" />
                <Setter Property="Shell.ShellTabBarForegroundColor" Value="{StaticResource ActionColor}"/>
                <Setter Property="Shell.ShellTabBarUnselectedColor" Value="{StaticResource LightGray}"/>
                <Setter Property="Shell.ShellTabBarTitleColor" Value="{StaticResource LightGray}"/>
            </Style>
            <Style TargetType="ShellItem" BasedOn="{StaticResource BaseStyle}" />
        </ResourceDictionary>
    </Shell.Resources>

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:sys="clr-namespace:System;assembly=mscorlib"
             x:Class="VisualChallenge.VisualChallengePage"
             Shell.NavBarIsVisible="true"
             Title="Edit Request"
             >
    
    <ContentPage.ToolbarItems>
        <ToolbarItem Text="Save"/>
    </ContentPage.ToolbarItems>
    
    <Shell.BackButtonBehavior>
        <BackButtonBehavior TextOverride="Undo" IconOverride="{OnPlatform Android=blanky}"></BackButtonBehavior>
    </Shell.BackButtonBehavior>

Expected Behavior

Consistent styling and visual between iOS and Android.

Basic Information

• Version with issue: 3.6-pre1
• Android 26

Screenshots

Parent: #2415

[rmarinho]

this was fixed by #5567