Expose proto package in plugin API

Some plugins, most notably index-elasticsearch module, might need to
depend on it.

Release-Notes: Expose proto package in plugin API
Change-Id: I9926fdce6de28f7696f79eda05c4fd3b3c698a74
diff --git a/plugins/BUILD b/plugins/BUILD
index 8eed4e8..aedcade 100644
--- a/plugins/BUILD
+++ b/plugins/BUILD
@@ -64,6 +64,7 @@
     "//java/com/google/gerrit/server/logging",
     "//java/com/google/gerrit/server/schema",
     "//java/com/google/gerrit/server/util/time",
+    "//java/com/google/gerrit/proto",
     "//java/com/google/gerrit/util/cli",
     "//java/com/google/gerrit/util/http",
     "//java/com/google/gerrit/util/logging",