build(deps): bump Xamarin.AndroidX.MediaRouter in /samples (#217)

Bumps [Xamarin.AndroidX.MediaRouter](https://github.com/xamarin/AndroidX) from 1.2.1 to 1.2.2.
- [Release notes](https://github.com/xamarin/AndroidX/releases)
- [Commits](https://github.com/xamarin/AndroidX/commits)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

samples/LoginApp.Forms.Android/LoginApp.Forms.Android.csproj

@@ -70,7 +70,7 @@
     <PackageReference Include="Xamarin.Android.Support.v4" Version="28.0.0.3" />
     <PackageReference Include="Xamarin.Android.Support.v7.CardView" Version="28.0.0.3" />
     <PackageReference Include="Xamarin.Android.Support.v7.MediaRouter" Version="28.0.0.3" />
-    <PackageReference Include="Xamarin.AndroidX.MediaRouter" Version="1.2.1" />
+    <PackageReference Include="Xamarin.AndroidX.MediaRouter" Version="1.2.2" />
     <PackageReference Include="Xamarin.AndroidX.Palette" Version="1.0.0.6" />
     <PackageReference Include="Xamarin.AndroidX.Preference" Version="1.1.1.7" />
   </ItemGroup>