Setting NODE_HOME to empty string for ubi-nodejs-extension

[pacostas]

Summary

• Node.js is packaged differently in ubi images. The base package for Node.js does not include the headers. There is another package nodejs-devel which includes the headers but while investigating this it seems like even if the package installed they won’t be used by default. We are discussing with the RHEL team and will likely update our extension to install that package and then set NODE_HOME to where they are installed but doing so today without some fixes might lead to different headers being in a rebuild. For now just set NODE_HOME env to an empty string so that the same headers will be used each time.

• We also discovered we were not making the node layer available during build which we should be to consistent with the non extension case.

Checklist

• I have viewed, signed, and submitted the Contributor License Agreement.
• I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• I have added an integration test, if necessary.
• I have reviewed the styleguide for guidance on my code quality.
• I'm happy with the commit history on this PR (I have rebased/squashed as needed).

[mhdawson]

LGTM