Add docs on how to test Android Apps

Contribution

[ ] I'd be willing to implement this feature (contributing guide)

Describe the user story

There are no comprehensive guides on https://testplane.io related to Android apps testing. This prevents users from using Testplane for that purpose even though it has such capabilities.

Describe the solution you'd like

Comprehensive guide on testplane.io

Describe the drawbacks of your solution

No response

Describe alternatives you've considered