Central pool of Android Virtual Devices to run tests

To speed up our Jenkins CI pipeline, we are looking for a solution to the long time it takes to get a new Android device up and running. We figured it would be nice to have a centralized back-end server running across multiple virtual devices (for example, different versions of Android) that can be used to run tests. This way we no longer need to run AVDs and we can reuse those resources for multiple projects.

I know some companies offer cloud instances for this (like Manymo) and some of them even offer nice integration with the Gradle build automation tool we use, but we'd love to run something on our own servers.

Does anyone know of an existing tool that can do this?

PS: I experimented over the weekend and I figured out some ways to achieve such a system, but I would rather not reinvent the wheel if the "wheel" is already created in that case.