Add DefaultContent API to retrieve apparmor profile content

The default apparmor profile is not stored on disk which causes
confusion when debugging the content of the profile. To solve this, we
now add an additional API which returns the profile as byte slice.

Signed-off-by: Sascha Grunert <sgrunert@suse.com>

pkg/apparmor/apparmor_unsupported.go

@@ -24,3 +24,8 @@ func CheckProfileAndLoadDefault(name string) (string, error) {
 	}
 	return "", ErrApparmorUnsupported
 }
+
+// DefaultContent dummy.
+func DefaultContent(name string) ([]byte, error) {
+	return nil, nil
+}