Revert the system clock in the debug oc-dev

System.currentTimeMillis does not guarantee to be monotonically
increasing, changed to SystemClock.elapsedRealtime

Bug: 38317243
Fixes: 38317243
Test: make -j 32; flash the angler device using local build
Change-Id: I775e6251f780679d639418a260c6d44c363a0c0f