Add Android integration test project

[sormuras]

Description

Directory https://github.com/junit-team/junit5/tree/master/platform-tooling-support-tests/projects already contains various gradle-xxx projects, but none using an Android environment.

https://github.com/junit-team/junit5-samples should also include an Android-based sample project.

Deliverables

• [ ] Creating integration test project using https://github.com/mannodermaus/android-junit5 -- @mannodermaus interested in providing a PR?
• [ ] Verify that logic using JMX presumably introduced by https://github.com/junit-team/junit5/pull/2026 doesn't break on Android.

[mannodermaus]

There already is a sample project in the android-junit5 repository, however it would be great to have one in the proper JUnit 5 space, too. I'll consider it for future submission through a PR when I find some time! 👍