chat/channel_test.go: the shell now implements LIFO shutdown.
chat/channel_test.go: the shell now implements LIFO shutdown.

Change-Id: Ifb8757608ccbe446dc24813bd2062a4d6d7d1f4d

vanadium/chat,viksit/chat,viksit/chat,viksit/chat,vanadium/chat,viksit/chat,vanadium/chat,viksit/chat,vanadium/chat,vanadium/chat