anago: add clarifying comment
anago: add clarifying comment

It is unclear in prepare_tree() calls why we'd have an input string
argument that is not already just "beta".  But apparently this happened in
in the past?  We definitely do want it normalized.  But that should also be
the case for other inputs too?

Signed-off-by: Tim Pepper <4807564e5a18784afafcf20dbdb5591e844b9075@vmware.com>

kubernetes/release,kubernetes/release