rxjava: add maven dependency

[StevenLuMT]

Descriptions of the changes in this PR:

Motivation

1. pr: BP-46: Data integrity check for running without journal #2936 miss rxjava maven dependency
2. the default workflow check just build with gradle,miss the maven build,so the problem of maven compilation is easy to be ignored, do we need to open maven compilation in default workflow?

Changes

rxjava: add maven dependency

PS

Bookkeeper committer I can't be missing......Ha Ha Ha

[StevenLuMT]

@eolivelli @pkumar-singh @zymap @Vanlightly
If you have time, please help me review it, thank you

[zymap]

I think we are aborting the Maven support and migrating to the Gradle. https://bookkeeper.apache.org/bps/BP-43-gradle-migration/. Could you please check the Gradle build is ok?

[StevenLuMT]

I think we are aborting the Maven support and migrating to the Gradle. https://bookkeeper.apache.org/bps/BP-43-gradle-migration/. Could you please check the Gradle build is ok?

yes,the Gradle build is ok, I have checked @zymap

[StevenLuMT]

@eolivelli @pkumar-singh @Vanlightly
If you have time, please help me review it, thank you

[pkumar-singh]

@StevenLuMT Yeah. Hopefully in a week or so we will be able to shutdown maven for good.

[dlg99]

No longer needed after #3009 and #3018