tests: set CanBePrefix in daemon tests

This commit also updates makeInterest and makeNack functions
so that their APIs are compatible with ndn-cxx test suite.

refs #4581

Change-Id: I0c81740416c26a03450dc3a12c89944b72ce5901
diff --git a/tests/daemon/face/lp-reliability.t.cpp b/tests/daemon/face/lp-reliability.t.cpp
index a4ec6d3..5e73c03 100644
--- a/tests/daemon/face/lp-reliability.t.cpp
+++ b/tests/daemon/face/lp-reliability.t.cpp
@@ -56,6 +56,7 @@
   {
     if (frags.front().has<lp::FragmentField>()) {
       Interest interest("/test/prefix");
+      interest.setCanBePrefix(false);
       lp::Packet pkt;
       pkt.add<lp::FragmentField>(make_pair(interest.wireEncode().begin(), interest.wireEncode().end()));
       m_reliability.handleOutgoing(frags, std::move(pkt), true);