Enable time based parallel for AQA test builds

[llxia]

In AQA test builds, not only do we support running parallel based on NUM_MACHINES, but we also support running parallel based on the expected completion time TEST_TIME. Once TEST_TIME is specified, the AQA test pipeline will try to meet this target by distributing tests across the necessary number of machines in parallel.

This functionality is designed for the cloud environment (e.g., fyre VM, Azure cloud, etc.). However, I believe we can activate it with a sensible TEST_TIME setting (e.g., TEST_TIME=120 mins) (without cloud environment) to avoid configuring numMachines individually for every test build in defaults.json. The current NUM_MACHINES solution could result in an extensive numMachines list, and it lacks the flexibility to adapt per platform.

ci-jenkins-pipelines/pipelines/defaults.json

Lines 75 to 77 in 6f9a96d

	"defaultDynamicParas": {
	"testLists" : ["extended.openjdk"],
	"numMachines" : ["3"]

https://github.com/ibmruntimes/ci-jenkins-pipelines/blob/3d327e6d8b6df1b2ce904493cd12566c4de4eebb/pipelines/defaults.json#L91-L94

FYI @smlambert @pshipton @AdamBrousseau