Remove redundant files from productized QS ZIP

7.2.0.GA.CR1 Quickstarts zip contains some files not relevant for product QS, please remove them:

• buildReadmes.sh
• CONTRIBUTING.md
• contributor-settings.xml

I am not sure about these:

• .mvn directory
• settings.xml - see the resolution of JBEAP-15884 whether this is needed or not

While none of these files causes issues when present in the ZIP, it can be confusing why they are included if not needed. None of the files were present in EAP 7.1.0.GA QS ZIP.