V1 runtime should not fail all any /admin requests if the host is not running

[ahmelsayed]

The only API that depends on the host being up is the invoke function. All other /admin APIs don't need that.

This is only relevant for v1 runtime, as #2005 handles that for v2

[mathewc]

Yes, we have special handling for the admin/host/status endpoint, but some of the other admin apis like keys we're not allowing through in host error conditions.