Change IaPrefixOption prefix length type to byte.

Given the maximum prefix length of IPv6 address is 128 and it
should not be assigned via IA prefix option to client, so S8
is enough to represent the prefix-length field.

Bug: 260934173
Test: m
Change-Id: Ia7fc52f7495775f3a29141d75adffafd84c38a02
1 file changed
tree: 895c1b5844f3c876b3a7827e21c973426b88335e
  1. staticlibs/