buildkit: Apply apparmor profile

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
(cherry picked from commit 611eb6ffb3)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

daemon/apparmor_default_unsupported.go

@@ -5,3 +5,8 @@ package daemon // import "github.com/docker/docker/daemon"
 func ensureDefaultAppArmorProfile() error {
 	return nil
 }
+
+// DefaultApparmorProfile returns an empty string.
+func DefaultApparmorProfile() string {
+	return ""
+}