@achystoprudov @markusschulte looks like it is working. I will just play around with it by creating a few more jobs and plans and confirm that nothing breaks now. 
@markusschulte I did not add “setAuthenticationContext” (the one in your source) and it still worked for me (with the workaround suggested by Alexey).
I just additionally added com.atlassian.bamboo.vcs.configuration.service.*:="optional" in my pom.xml which was missing in your pom.xml.
@acalantog and @achystoprudov @markusschulte thanks a ton !!!