Add tests for host entries resolved via /etc/hosts

These ensure we don't send out actual DNS queries for localhost and
ip6-localost.

Test: atest netd_integration_test
Change-Id: I918f2e870c4f50ad05f858e5d3c6cc225955d982
diff --git a/tests/binder_test.cpp b/tests/binder_test.cpp
index 955a769..0410532 100644
--- a/tests/binder_test.cpp
+++ b/tests/binder_test.cpp
@@ -720,7 +720,6 @@
 static bool interfaceHasAddress(
         const std::string &ifname, const char *addrString, int prefixLength) {
     struct addrinfo *addrinfoList = nullptr;
-    ScopedAddrinfo addrinfoCleanup(addrinfoList);
 
     const struct addrinfo hints = {
         .ai_flags    = AI_NUMERICHOST,
@@ -731,6 +730,7 @@
         addrinfoList == nullptr || addrinfoList->ai_addr == nullptr) {
         return false;
     }
+    ScopedAddrinfo addrinfoCleanup(addrinfoList);
 
     struct ifaddrs *ifaddrsList = nullptr;
     ScopedIfaddrs ifaddrsCleanup(ifaddrsList);