Don't shut down already-shutdown IM objects. (#7627)
Don't shut down already-shutdown IM objects. (#7627)

Shutting down things that are not in use already leads to pretty
confusing logging/debugging behavior.
project-chip/connectedhomeip,project-chip/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,project-chip/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,nestlabs/connectedhomeip,project-chip/connectedhomeip