Configure aplay service to restart on failure

[besi]

Add restart policy for aplay service

See #368

[makermelissa]

My concern with this addition is that it may cause a restart loop on the service if it keeps failing. Did you try restarting again after the failure and this was the only way to get it to start?

[besi]

Once the Pi was started a manual restart did work without a problem.
That's why I came up with the restart work around since it did the trick on my system.

However, maybe the service starts too soon upon boot and some pre-condition may be required instead?
This could be a more clean solution.

sudo journalctl | grep error
Feb 04 14:08:12 stereopida aplay[242]: aplay: main:831: audio open error: No such file or directory
Feb 04 14:08:38 stereopida alsactl[426]: alsa-lib main.c:1541:(snd_use_case_mgr_open) error: failed to import hw:0 use case configuration -2