Added manifest entry to the eventbus-java jar file

[plumstone]

trafficstars

Solves the warning mentioned in https://github.com/greenrobot/EventBus/issues/507

[greenrobot-team]

Thanks! We'll have a look at some point if that is enough (note: I remember something about package names not being allowed to overlap, need to check if the Android artifact ever is supposed to use modules, too).

[plumstone]

The build failed due to an error in the jdk setup process. Maybe we should consider updating the jdk to temurin (successor of adopt) https://github.com/actions/setup-java#basic

[greenrobot-team]

@plumstone Thanks for the info! Fixed in master branch, e.g. rebase your change onto or merge the changes from master.