When users request that the container keep a console ringbuffer we will not
continously write to the on-disk logfile as mirroring the contents of the
in-memory ringbuffer on-disk is costly and complicated. Instead, we dump the
ringbuffer contents on-disk when the container stops or fails to start. This
way users can still diagnose problems or retrieve the last contents of the
ringbuffer on-disk.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>