UIDMapping/GIDMapping Support

Is there a way to support UIDMapping/GIDMapping using nri?

```
// PodSandbox linux-specific metadata
type LinuxPodSandbox struct {
// UIDMapping specifies user mappings for supporting user namespaces.
UIDMappings []LinuxIDMapping `json:"uidMappings,omitempty"`
// GIDMapping specifies group mappings for supporting user namespaces.
GIDMappings []LinuxIDMapping `json:"gidMappings,omitempty"`

state protoimpl.MessageState
sizeCache protoimpl.SizeCache
unknownFields protoimpl.UnknownFields
....
Namespaces []*LinuxNamespace `protobuf:"bytes,5,rep,name=namespaces,proto3" json:"namespaces,omitempty"` // for NRI v1 emulation
Resources *LinuxResources `protobuf:"bytes,6,opt,name=resources,proto3" json:"resources,omitempty"` // for NRI v1 emulation

```
}