[mdns] remove deprecated_bare_package_url from BUILD.gn

This CL removes the deprecated_bare_package_url annotation from the
BUILD.gn file. It also replaces the "binary" parameter of the package
target in favor of "binaries" and names the binary "bin/mdns" in the
cmx file.

TEST: no behavior change, tested for regressions by booting and
      observing logs

CF-295 #done

Change-Id: Ife63c434165a2f759b98b96c04a201aed996ed15
diff --git a/bin/mdns/service/BUILD.gn b/bin/mdns/service/BUILD.gn
index 53c279d..801d5d5 100644
--- a/bin/mdns/service/BUILD.gn
+++ b/bin/mdns/service/BUILD.gn
@@ -101,13 +101,15 @@
 }
 
 package("service") {
-  deprecated_bare_package_url = "//build"
-
   deps = [
     ":bin",
   ]
 
-  binary = "mdns"
+  binaries = [
+    {
+      name = "mdns"
+    },
+  ]
 
   package_name = "mdns"
 
diff --git a/bin/mdns/service/meta/mdns.cmx b/bin/mdns/service/meta/mdns.cmx
index 4ec7c06..c225113 100644
--- a/bin/mdns/service/meta/mdns.cmx
+++ b/bin/mdns/service/meta/mdns.cmx
@@ -1,6 +1,6 @@
 {
     "program": {
-        "binary": "bin/app"
+        "binary": "bin/mdns"
     },
     "sandbox": {
         "services": [