Revert "Made WinUI branding colors overridable"

This reverts commit e957f39.

Author: imalcolm1

GeneratedResources/WinUI/Colors/Brushes.xaml

@@ -1,5 +1,8 @@
 <ResourceDictionary
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <ResourceDictionary.MergedDictionaries>
+        <ResourceDictionary Source="ms-appx:///Esri.Calcite.WinUI/Colors/Colors.xaml" />
+    </ResourceDictionary.MergedDictionaries>
             <SolidColorBrush x:Key="CalciteBackgroundBrush" Color="{ThemeResource CalciteBackgroundColor}" />
             <SolidColorBrush x:Key="CalciteBackgroundNoneBrush" Color="{ThemeResource CalciteBackgroundNoneColor}" />
             <SolidColorBrush x:Key="CalciteBorder1Brush" Color="{ThemeResource CalciteBorder1Color}" />

src/Esri.Calcite.WinUI/Styles/Brushes.xaml

@@ -1,4 +1,8 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <ResourceDictionary.MergedDictionaries>
+        <ResourceDictionary Source="ms-appx:///Esri.Calcite.WinUI/Colors/Brushes.xaml" />
+    </ResourceDictionary.MergedDictionaries>
+
     <ResourceDictionary.ThemeDictionaries>
         <ResourceDictionary x:Key ="Default" >
             <Color x:Key="CalciteTextOnBrandColor">White</Color>

src/Esri.Calcite.WinUI/Styles/Controls/Buttons.xaml

@@ -3,6 +3,10 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:cal="using:Esri.Calcite.WinUI"
     >
+    <ResourceDictionary.MergedDictionaries>
+        <ResourceDictionary Source="ms-appx:///Esri.Calcite.WinUI/Styles/Fonts.xaml" />
+        <ResourceDictionary Source="ms-appx:///Esri.Calcite.WinUI/Styles/Brushes.xaml" />
+    </ResourceDictionary.MergedDictionaries>
 
     <StaticResource x:Key="ButtonBackground" ResourceKey="CalciteBackground3Brush" />
     <StaticResource x:Key="ButtonBackgroundPointerOver" ResourceKey="CalciteBackground2Brush" />

src/Esri.Calcite.WinUI/Styles/Controls/TextBox.xaml

@@ -1,6 +1,10 @@
 <ResourceDictionary
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <ResourceDictionary.MergedDictionaries>
+        <ResourceDictionary Source="ms-appx:///Esri.Calcite.WinUI/Styles/Fonts.xaml" />
+        <ResourceDictionary Source="ms-appx:///Esri.Calcite.WinUI/Colors/Brushes.xaml" />
+    </ResourceDictionary.MergedDictionaries>
 
     <StaticResource x:Key="TextControlBorderBrush" ResourceKey="CalciteBorder2Brush" />
     <StaticResource x:Key="TextControlBackground" ResourceKey="CalciteBackground1Brush" />

src/TestApps/WinUITests/App.xaml

@@ -15,23 +15,6 @@
                         <CalciteResources xmlns="using:Esri.Calcite.WinUI" />
                     </XamlControlsResources.MergedDictionaries>
                 </XamlControlsResources>
-                
-                <!-- Merge in XAML resource overrides -->
-                <ResourceDictionary>
-                    <!-- Override brand colors -->
-                    <!--<ResourceDictionary.ThemeDictionaries>
-                        <ResourceDictionary x:Key="Default">
-                            <Color x:Key="CalciteBrandColor" >#8F53CA</Color>
-                            <Color x:Key="CalciteBrandHoverColor" >#7938B6</Color>
-                            <Color x:Key="CalciteBrandPressColor" >#652E98</Color>
-                        </ResourceDictionary>
-                        <ResourceDictionary x:Key="Dark">
-                            <Color x:Key="CalciteBrandColor" >#7938B6</Color>
-                            <Color x:Key="CalciteBrandHoverColor" >#652E98</Color>
-                            <Color x:Key="CalciteBrandPressColor" >#51247A</Color>
-                        </ResourceDictionary>
-                    </ResourceDictionary.ThemeDictionaries>-->
-                </ResourceDictionary>
             </ResourceDictionary.MergedDictionaries>
             <!-- Other app resources here -->
             <Style TargetType="TextBlock" x:Key="CodeTextBlock">