How to build tests that mix service platform data inputs with mobile device responses?

I have a system to test that includes a public facing restful services platform and a (Android) mobile device that both sends data to this platform but also receives notifications from the platform - via Google Cloud messaging.

My test plan has three basic core scenarios:

Scenario #1

• Have a command line utility that pushes data into the restful services platform. This data injection should trigger a notification to the mobile device
• Test that the mobile device has received the notification.

Scenario #2

• Have the mobile device app perform an action that ends up sending data to the services platform
• Run a command line utility that checks whether the platform can be queried to return the same data

Scenario #3 (a variation of scenario #1)

• Push some data into the platform
• Test whether the mobile device has received a notification
• Push a second data change into the platform
• Test whether the mobile device has received this second notification

I want to build automated tests for both these scenarios. Because the mobile device app has a large amount of business logic, I want to include the mobile app as an actor in these tests. I'm looking at using one of the many 'device in the cloud' services (e.g. SauceLabs, Perfecto, AWS device farm) that allows a mobile app to be used as a testing vehicle.

The problem I'm struggling to reconcile is how can I setup a test suite that is running two different actors: a command line actor that is pushing data into the services, and a second actor (the device) that is checking for notifications. Also how to reconcile the step wise nature of scenario #3

Thoughts?