The current timer modification API does not return the status
of the underlying OS specific API.
The return status of the underlying API could be useful
to detect if the timer was modified even before the timer
has expired before the last update to the timer.
Update the API to return the status of the underlying API.
CRs-Fixed: 2835319
Change-Id: Ieade0ff82386f959d7f29264a25b75a96a72e644