Update AndroidFramebuffer.cs

[corvinsz]

Fixes typo: "... that are show ..." --> "... that are shown ..."

What does the pull request do?

Fixes a typo

What is the current behavior?

What is the updated/expected behavior with this PR?

How was the solution implemented (if it's not obvious)?

Checklist

• [ ] Added unit tests (if possible)?
• [x] Added XML documentation to any related classes?
• [ ] Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with user documentation

Breaking changes

Obsoletions / Deprecations

Fixed issues

[avaloniaui-bot]

You can test this PR using the following package version. 11.3.999-cibuild0053237-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[cla-avalonia]

• [x] All contributors have signed the CLA.

[corvinsz]

@cla-avalonia agree