bluetooth: Request headset audio during profile switch
When a headset is having a profile switch, we can either leave the
SCO state unmodified (as it was before this patch) or we can
alternatively request it (as older versions of PA).
This patch tries to avoid a potential regression in case a module
such as module-suspend-on-idle is not present, due to the provided
resume-on-running policy. Without this patch, and without such a policy,
the sink and sources would stay suspended until the user manually
performed another profile switch (i.e. hsp->off->hsp).
There are several other solutions currently being discussed as a longer
term solution, some of which require extendind the core. This patch is
therefore proposed as a short-term workaround to avoid the regression.