card-restore: don't switch profiles when availability changes

card-restore: don't switch profiles when availability changes

module-card-restore should only restore the initial state of new
cards, but profile_available_changed_callback() changed the profile
whenever the saved profile became available. That caused interference
with module-bluetooth-policy, which also sets card profiles based on
the availability changes.

The original reason for having this code was to work around the
problem that bluetooth cards used to be created with only one profile
available, and other profiles would become available soon after the
card creation. Now the bluetooth card creation is delayed until all
profiles are available, so this bad workaround can be removed.

Discussion:
https://lists.freedesktop.org/archives/pulseaudio-discuss/2016-August/026575.html