leaudio: Fix switching Active group

With this patch GROUP_STATUS_CHANGED is sent if

1) First new active group has been succesfully set
2) Requested active group is already set
3) Active group has been removed (set to -1)
4) Active group has been switch to new one.

In case of 4) audio stream is closed for the previous group.

Fixes issue with switching between two Le Audio sets.

Bug: 150670922
Sponsor: @jpawlowski
Test: Manual test with 2 Le Audio sets
Change-Id: I0e33fe27f21b59f40e0cd1278e2020e8bd79cde2