unified the simulation time

[kemen209]

make it work under steppable-clock.

Maybe related to #3010.

[ghost]

All CLA requirements met.

[zimmy87]

Hi @kemen209, how was this PR tested?

[kemen209]

Hi @zimmy87, i try the following setting on my local machine:

setting.json

"ClockType": "SteppableClock",
"ClockSpeed": 1.0,

And i use some debugging trick to slow down the simu clock, and it worked as i expected: simu clock only move one step, but the wall clock may passed hundreds of seconds.

Besides this, no other tests, like auto test involved.

From my understanding, this bug only a problem when use 'SteppableClock' with slow or faster simu clock.

[zimmy87]

Thank you for submitting this PR @kemen209! I tested this locally and it appears to work as intended, so I am merging this. This also fixed #3010 for me, so I will refer people to this fix in that issue.