Java gRPC client for Armada

[mladjan-gadzic]

Is your feature request related to a problem? Please describe.
There is a need to support Jenkins Agents as Armada jobs. To do so Armada Jenkins plugin will be created. Since Jenkins is written in Java it is only natural to have Java client for Armada.

Describe the solution you'd like
Autogenerated Java sources from Armada API .proto files.
Unit and integration tests.

Describe alternatives you've considered

Additional context

[mladjan-gadzic]

this is the repo of java grpc client for armada https://github.com/mladjan-gadzic/armada-grpc-java-client

todo:

• add tests
• include java grpc client for armada in armada clients