Appium configurations breaks when multiple environments are active

[SimonStefan]

What happened?

For more complex setups it would be nice to avoid duplication of properties in serenity.conf and split it up in different environments and choose which should be active.

For example:

environments {
  android {
    ...
  }
  ios {
    ...
  }

  dev {
    ...
  }
  prod {
    ...
  }
}

There is already the concept to select multiple environments with defining them separated with a comma (environment=android,dev)

However when using Appium this is not possible and fails in AppiumConfiguration.java as it does not find the corresponding properties correctly

What did you expect to happen?

Appium configuration should take all properties from environments.android.* and environments.dev.*

Serenity BDD version

5.3.11

JDK version

17

Execution environment

macOS Tahoe

How to reproduce the bug.

Keep the serenity.conf untouched and just add any second environment to environment, separated with a comma

How can we make it happen?

Work on this myself and propose a PR (with Serenity BDD team guidance)