Decrease number of sElapsedRealtimeClock.millis() calls in Flexibility Controller

Getting the current elapsed time is system intensive. Currently
flexibility controller gets the elapsed time within for loops and in
functions that are called at the same time. By passing in nowElapsed we
can decrease the amount of times we call sElapsedRealtimeClock.millis().

Bug: 243166228

Test: atest frameworks/base/services/tests/mockingservicestests/src/com/android/server/job
Test: atest frameworks/base/services/tests/servicestests/src/com/android/server/job
Test: atest CtsJobSchedulerTestCases
Change-Id: I8bed88b97306af0fc7d0beadb43cb252ad0d5afe