Cache Maven Repository during AWS Test Execution

The aws-test job utilizes maven, but not via the .maven template. But, nobody likes downloading dependencies over and over and over. This introduces a simple cache of the .m2/repository; more or less copy-pasted from the maven.yml file.

For testing, note Job 10949 builds as normal, but ends with the lines:

 Creating cache default...
/builds/osdu/platform/system/search-service/.m2/repository: found 4941 matching files 
No URL provided, cache will be not uploaded to shared cache server. Cache will be stored only locally. 

A subsequent execution, Job 10950 runs without having to download any dependencies. Yay!

As the good runner said, the cache is stored locally on the machine that does the execution. So, if we have multiple different machines running this job (and we do), they will each have an independent cache. Not a problem, of course, just something to keep in mind if you're curious why you are getting dependency downloads in a particular execution.