google::protobuf::uint64 is changing from unsigned long long to
uint64_t, which is sometimes unsigned long long and sometimes
unsigned long. Add a SetValue specialization for unsigned long.
Mark both the unsigned long and unsigned long long specializations
as sometimes unused, they will be unused if uint64_t is the other.
Bug: 117607748
Test: m checkbuild
Change-Id: I8bec0be6cd7e13354cf96a7e510fe2b920aec561