Fix wait/notify logic in GNSS VTS 2.0 test cases (part 2)

Addresses follow up code review comments after merge of ag/7324643.

Fixes: 131869042
Test: atest VtsHalGnssV2_0TargetTest
Change-Id: I0177ee60c5edfb6855ce6a1d45b8805166a33cf2
3 files changed