Fix incorrect reference to the gRPC runtime name as a binary
Fix incorrect reference to the gRPC runtime name as a binary

Until we have a way to preserve the initial command used to start the
container, we have to default to the default `runc` found on the $PATH.
This code after the last refactor of shim/API is incorrectly using the
gRPC object reference of the v1 runtime as a binary name which causes
os.Exec() errors.

Signed-off-by: Phil Estes <dbac1f450dc8326caa7ba104b384a0eca642250c@gmail.com>
Signed-off-by: Phil Estes <dbac1f450dc8326caa7ba104b384a0eca642250c@linux.vnet.ibm.com>

containerd/containerd,estesp/containerd,mikebrow/containerd,thaJeztah/containerd,miaoyq/containerd,AkihiroSuda/containerd,chanezon/containerd,dmcgowan/containerd,crosbymichael/containerd,rajasec/containerd,vdemeester/containerd,dmcgowan/containerd,miaoyq/containerd,estesp/containerd,mikebrow/containerd,containerd/containerd,vdemeester/containerd,hqhq/containerd,crosbymichael/containerd,kunalkushwaha/containerd,kunalkushwaha/containerd,thaJeztah/containerd