Expose vars to configure an additional runtime handler
Expose vars to configure an additional runtime handler

Expose environment variables in the GCE containerd configuration
script for configuring an additional runtime handler. This unblocks
E2E testing of custom runtime handlers.

Signed-off-by: Tim Allclair <2125713a184129867c2009b68c5a7fe6fb4f766a@google.com>

dmcgowan/containerd,mikebrow/containerd,containerd/containerd,estesp/containerd,thaJeztah/containerd,vdemeester/containerd,estesp/containerd,containerd/containerd,mikebrow/containerd,vdemeester/containerd,thaJeztah/containerd,dmcgowan/containerd