Create file "ext_mapping.conf.json"

.mapping.json

@@ -59,6 +59,7 @@
   "README.md":"ydb/github_toplevel/README.md",
   "ROADMAP.md":"ydb/github_toplevel/ROADMAP.md",
   "SECURITY.md":"ydb/github_toplevel/SECURITY.md",
+  "build/ext_mapping.conf.json":"ydb/github_toplevel/build/ext_mapping.conf.json",
   "build/internal/conf/internal.conf":"ydb/github_toplevel/build/internal/conf/internal.conf",
   "build/internal/ya.conf":"ydb/github_toplevel/build/internal/ya.conf",
   "build/mapping.conf.json":"devtools/ya/opensource/mapping.conf.json",

build/ext_mapping.conf.json

@@ -0,0 +1,10 @@
+{
+    "bottles": {},
+    "resources": {
+        "678806418": "http://ydb-tech-ci.storage.yandexcloud.net/ydb-platform/resources/678806418"
+    },
+    "resources_descriptions": {
+        "678806418": "Pg Linux pack"
+    },
+    "tasks": {}
+}