Fix maven CC Report enabling

[nigurr]

• Fixed issue when Maven project contains both plugin management and plugins, append CC reporting to plugins instead of plugin management
• UTs are added
• Manual testing done

[allendm-msft]

Seems fine. Wait on Yang to signoff

[yacaovsnc]

In general it looks good to me. I am not sure if you need to modify <pluginsManagement> section at all. However I also don't know all the scenarios, so if you think it's necessary, that probably doesn't hurt anyway.

[nigurr]

@yacaovsnc, we have few scenarios where it's required :)