Gnss measurements session that is started to
collect Gnss measurements needs to be stoped
when closed.
Also remove the ability for an MSA tracking
session to be started when Gnss measurments is
started because MSA tracking is power hungry
and it wouldn't provide measurements either
Change-Id: I9b20f73bd412fc68d96dad2dc38399c144922ea0
CRs-fixed: 2039306