When building Launcher3 target, LauncherDumpProto class should not be proguarded
b/36904684

Change-Id: I0fd0e1c63d54d83db428a04067a37f582e4d23f1
diff --git a/proguard.flags b/proguard.flags
index 6cbab08..8ee6ccd 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -94,3 +94,7 @@
 -keep interface com.android.launcher3.userevent.nano.LauncherLogProto.** {
   *;
 }
+
+-keep interface com.android.launcher3.model.nano.LauncherDumpProto.** {
+  *;
+}