Add missed discoverable policy rules for flavor-manage v3

Add discoverable policy rule for v3 extension flavor-manage,
Although without this patch, it also works. But that's used to
indicate to user there is option for flavor-manager discoverable.

Change-Id: I23f8bbaccfa104a12e4a4c9eea8bf04107b57d43
Merge "Add missed discoverable policy rules for flavor-manage v3"