Stop respawning serial console if disabled

After introducing ro.boot.serialconsole=0, the console will no longer be
spawned, but a step was missed to disable the service to prevent
respawns.

Bug: 266982931
Bug: 223797063
Bug: 267428635
Change-Id: I12b159eaa1999781aec31c05ce431b55e2ba4017
1 file changed