Put address_sorting's public header under its own directory. Also add
test_only to sort function used in test.
diff --git a/package.xml b/package.xml
index dd50e6b..dc2eb42 100644
--- a/package.xml
+++ b/package.xml
@@ -51,8 +51,8 @@
     <file baseinstalldir="/" name="src/php/ext/grpc/server_credentials.h" role="src" />
     <file baseinstalldir="/" name="src/php/ext/grpc/timeval.h" role="src" />
     <file baseinstalldir="/" name="src/php/ext/grpc/version.h" role="src" />
-    <file baseinstalldir="/" name="third_party/address_sorting/address_sorting.h" role="src" />
     <file baseinstalldir="/" name="third_party/address_sorting/address_sorting_internal.h" role="src" />
+    <file baseinstalldir="/" name="third_party/address_sorting/include/address_sorting/address_sorting.h" role="src" />
     <file baseinstalldir="/" name="third_party/address_sorting/address_sorting.c" role="src" />
     <file baseinstalldir="/" name="third_party/address_sorting/address_sorting_posix.c" role="src" />
     <file baseinstalldir="/" name="third_party/address_sorting/address_sorting_windows.c" role="src" />