Bump Xamarin.AndroidX.Navigation.UI from 2.4.2.1 to 2.5.1

Bumps [Xamarin.AndroidX.Navigation.UI](https://github.com/xamarin/AndroidX) from 2.4.2.1 to 2.5.1.
- [Release notes](https://github.com/xamarin/AndroidX/releases)
- [Commits](https://github.com/xamarin/AndroidX/commits)

---
updated-dependencies:
- dependency-name: Xamarin.AndroidX.Navigation.UI
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

eng/AndroidX.targets

@@ -18,7 +18,7 @@
     />
     <PackageReference
         Update="Xamarin.AndroidX.Navigation.UI"
-        Version="2.4.2.1"
+        Version="2.5.1"
     />
     <PackageReference
         Update="Xamarin.AndroidX.Navigation.Fragment"