unit: drop console-shell.service (#4298) (#4325)

console-shell.service was supposed to be useful for normal clean boots
(i.e. multi-user.target or so), as a replacement for logind/getty@.service for
simpler use cases.

But due to the lack of documentation and sanity check one can easily be
confused and enable this service in // with getty@.service.

In this case we end up with both services sharing the same tty which ends up in
strange results.

Even worse, console-shell.service might be failing while getty@.service tries
to acquire the terminal which ends up in the system to poweroff since
console-shell.service uses:

  "ExecStopPost=-/usr/bin/systemctl poweroff".

Another issue: this service doesn't work well if plymouth is also used since it
lets the splash screen program run and mess the tty (at least a "plymouth quit"
is missing).

So let's kill it for now.

Makefile.am

@@ -524,7 +524,6 @@ dist_systemunit_DATA_busnames += \
 nodist_systemunit_DATA = \
 	units/getty@.service \
 	units/serial-getty@.service \
-	units/console-shell.service \
 	units/console-getty.service \
 	units/container-getty@.service \
 	units/systemd-initctl.service \
@@ -587,7 +586,6 @@ dist_systempreset_DATA = \
 EXTRA_DIST += \
 	units/getty@.service.m4 \
 	units/serial-getty@.service.m4 \
-	units/console-shell.service.m4.in \
 	units/console-getty.service.m4.in \
 	units/container-getty@.service.m4.in \
 	units/rescue.service.in \

system-preset/90-systemd.preset

@@ -18,7 +18,6 @@ enable systemd-resolved.service
 enable systemd-networkd-wait-online.service
 
 disable console-getty.service
-disable console-shell.service
 disable debug-shell.service
 
 disable halt.target

units/.gitignore

@@ -1,8 +1,6 @@
 /user@.service.m4
 /console-getty.service
 /console-getty.service.m4
-/console-shell.service
-/console-shell.service.m4
 /container-getty@.service
 /container-getty@.service.m4
 /debug-shell.service