For a project we have three separate jobs:
1. Installs the SDK and creates build files
2. Builds the s/w
3. Builds the tests, starts an emulator and executes tests

The problem that I run into is that the system images aren't installed. After some experimentation I figured out the following: The "Install Android project prerequisites" build step only installs system images when the job also has an fully configured emulator enabled.

Adding an "Install Android project prerequisites" build step in the same job (third) as the which holds the emulator configuration, the system images won't be installed. In this instance it's only checked if the SDK is available, not if it also includes the system images.