Do not trace dead fields in Enqueuer

Change-Id: I40e6f07e64482e02f4a4d32cca20f9697f42e139
diff --git a/tools/youtube_data.py b/tools/youtube_data.py
index f26af8d..94a97ce 100644
--- a/tools/youtube_data.py
+++ b/tools/youtube_data.py
@@ -131,6 +131,7 @@
       'pgconf': [
           '%s_proguard.config' % V14_19_PREFIX,
           '%s/proguardsettings/YouTubeRelease_proguard.config' % utils.THIRD_PARTY],
+      'proto-shrinking': 1,
       # Build for native multi dex, as Currently R8 cannot meet the main-dex
       # constraints.
       #'maindexrules' : [