Further reduce the use of std::bind()

And also avoid deprecated ndn-cxx type aliases

Change-Id: I87e903b9671a3cf1c1b9ab30d4594d595c3c6da9
diff --git a/daemon/fw/unsolicited-data-policy.cpp b/daemon/fw/unsolicited-data-policy.cpp
index 8ad0f66..c1a7358 100644
--- a/daemon/fw/unsolicited-data-policy.cpp
+++ b/daemon/fw/unsolicited-data-policy.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  Regents of the University of California,
+ * Copyright (c) 2014-2023,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -66,7 +66,6 @@
   return policyNames;
 }
 
-const std::string DropAllUnsolicitedDataPolicy::POLICY_NAME("drop-all");
 NFD_REGISTER_UNSOLICITED_DATA_POLICY(DropAllUnsolicitedDataPolicy);
 
 UnsolicitedDataDecision
@@ -75,7 +74,6 @@
   return UnsolicitedDataDecision::DROP;
 }
 
-const std::string AdmitLocalUnsolicitedDataPolicy::POLICY_NAME("admit-local");
 NFD_REGISTER_UNSOLICITED_DATA_POLICY(AdmitLocalUnsolicitedDataPolicy);
 
 UnsolicitedDataDecision
@@ -87,7 +85,6 @@
   return UnsolicitedDataDecision::DROP;
 }
 
-const std::string AdmitNetworkUnsolicitedDataPolicy::POLICY_NAME("admit-network");
 NFD_REGISTER_UNSOLICITED_DATA_POLICY(AdmitNetworkUnsolicitedDataPolicy);
 
 UnsolicitedDataDecision
@@ -99,7 +96,6 @@
   return UnsolicitedDataDecision::DROP;
 }
 
-const std::string AdmitAllUnsolicitedDataPolicy::POLICY_NAME("admit-all");
 NFD_REGISTER_UNSOLICITED_DATA_POLICY(AdmitAllUnsolicitedDataPolicy);
 
 UnsolicitedDataDecision