Skip publishing if sample app build fails

[sync-by-unito]

There is something wrong with the exit status of the 'Tests Android Sample App' step of our Jenkins build.

In this build the sample app tests failed but I had to abort the publishing manually: https://ci.realm.io/blue/organizations/jenkins/realm%2Frealm-kotlin/detail/master/66/pipeline

[nhachicha]

@rorbech I think this could be achieved simply by adding the currentBuild.result to the check in https://github.com/realm/realm-kotlin/blob/master/Jenkinsfile#L85 to avoid starting this stage at all

[rorbech]

Seems like there is still an issue not aborting the build if the sample app fails: https://ci.realm.io/blue/organizations/jenkins/realm%2Frealm-kotlin/detail/master/360/pipeline