chore: Add readme to samples

[justin-fiedler]

Summary

Added READMEs to the sample Android apps

Checklist

• [x] Does your PR title have the correct title format?
• Does your PR have a breaking change?: Nope

[github-actions[bot]]

:tada: This PR is included in version 1.10.3 :tada:

The release is available on:

• GitHub release
• v1.10.3

Your semantic-release bot :package::rocket: