AudioPolicy: enforce hw volume application rule

This CL enforces the rules of hw volume application:
-apply only if a strategy following the group is active
-do not apply if another client is active with higher priority
than the highest priority active strategy following the
volume group.

It enforces also checkAndSetVolume that may be called when an
output is started / stopped, ....When using Hw Volume, starting
a client on the same output than already active client may lead
to unwanted volume change, depending of the volume group followed
by each client.

Bug: 270049944
Test: atest AudioManagerTest
Flag: android.media.audiopolicy.volume_group_management_update

Change-Id: I082c6a12ac7f240f7147116cc913ff1332a38360
Signed-off-by: François Gaffie <francois.gaffie@renault.com>