Support runtime watchdog
Previously, systemd did not support to change runtime watchdog.
However, recent systemd supports such functionality - https://github.com/systemd/systemd/commit/
2787d83c2.
Thus, argos watchdog supports the feature.
Thanks to Mr.Sung(JungHak) (Original Idea from him)
Change-Id: I8ef1741c16867e46329c529365726821dd5d44d1