build: Bump android app to level 9.0

XamlControlsGallery.Droid/Properties/AndroidManifest.xml

@@ -1,9 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
-					package="com.nventive.xamlcontrolsgallery" 
-					android:versionCode="35" 
-					android:versionName="1.0" 
-					android:installLocation="auto">
-	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="26" />
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.nventive.xamlcontrolsgallery" android:versionCode="35" android:versionName="1.0" android:installLocation="auto">
+	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="28" />
 	<application android:label="XAML Controls Gallery"></application>
 </manifest>

XamlControlsGallery.Droid/XamlControlsGallery.Droid.csproj

@@ -16,7 +16,7 @@
     <AndroidResgenFile>Resources\Resource.Designer.cs</AndroidResgenFile>
     <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
     <AndroidUseLatestPlatformSdk>False</AndroidUseLatestPlatformSdk>
-    <TargetFrameworkVersion>v8.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v9.0</TargetFrameworkVersion>
     <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
     <AndroidUseIntermediateDesignerFile>True</AndroidUseIntermediateDesignerFile>
     <ResourcesDirectory>..\AppUIBasics.Shared\Strings</ResourcesDirectory>