Introduce Windows WSL implementation of podman machine

[NO NEW TESTS NEEDED] for now

Signed-off-by: Jason Greene <jason.greene@redhat.com>

vendor/github.com/containers/common/pkg/config/default_linux.go

@@ -13,6 +13,17 @@ const (
 	oldMaxSize = uint64(1048576)
 )
 
+// getDefaultMachineImage returns the default machine image stream
+// On Linux/Mac, this returns the FCOS stream
+func getDefaultMachineImage() string {
+	return "testing"
+}
+
+// getDefaultMachineUser returns the user to use for rootless podman
+func getDefaultMachineUser() string {
+	return "core"
+}
+
 // getDefaultRootlessNetwork returns the default rootless network configuration.
 // It is "slirp4netns" for Linux.
 func getDefaultRootlessNetwork() string {