The connection event at the connection update instant was
skipped due to previous ticker node in use that is being
stopped was registering a relative occupied time that
overlapped with the new ticker node being started for
scheduling the connection with new interval.
Added mock interface for ticker_stop_abs() hence needed by
the Controller unit testing.
Signed-off-by: Vinayak Kariappa Chettimada <vich@nordicsemi.no>
5dffad061c