The following configuration of the android-maven-plugin will not find the running emulator on Jenkins.
Commenting this line will find the emulator.
On my local machine this is working fine, but not in Jenkins.
Both machines use maven 3.0.4 on Linux/Ubuntu.

<groupId>com.jayway.maven.plugins.android.generation2</groupId>
<artifactId>android-maven-plugin</artifactId>
<configuration>
...
<device>emulator</device>
...
</configuration>
</plugin>

This configuration is useful on the local machine, if you are developing while charging your phone via USB.
Best regards, that's a really nice plugin!
Sebl29