Add extra proguard configurations for GmsCore.

R=tamaskenez@google.com

Bug:
Change-Id: Ica7c28abed2b2c3567d710a4552a0b3e76157677
diff --git a/tools/gmscore_data.py b/tools/gmscore_data.py
index 5585322..47d9024 100644
--- a/tools/gmscore_data.py
+++ b/tools/gmscore_data.py
@@ -116,7 +116,9 @@
   'latest': {
     'deploy' : {
       'inputs': ['%s_deploy.jar' % LATEST_PREFIX],
-      'pgconf': ['%s_proguard.config' % LATEST_PREFIX],
+      'pgconf': [
+          '%s_proguard.config' % LATEST_PREFIX,
+          '%s/proguardsettings/GmsCore_proguard.config' % THIRD_PARTY],
       'min-api' : ANDROID_L_API,
     },
   },