Make the BattOr agent retry start tracing when we fail to read an ack

tools/battor_agent/battor_error.cc

Index: tools/battor_agent/battor_error.cc
diff --git a/tools/battor_agent/battor_error.cc b/tools/battor_agent/battor_error.cc
index ba0b1c076e12e15f58646abc22c25bbe3be4d327..bf3bf93f1f34e1f43212ea7dcf9dc49c6fc61bd2 100644
--- a/tools/battor_agent/battor_error.cc
+++ b/tools/battor_agent/battor_error.cc
@@ -24,6 +24,8 @@ std::string BattOrErrorToString(BattOrError error) {
       return "UNEXPECTED MESSAGE";
     case BATTOR_ERROR_TOO_MANY_INIT_RETRIES:
       return "TOO MANY INIT RETRIES";
+    case BATTOR_ERROR_TOO_MANY_START_TRACING_RETRIES:
+      return "TOO MANY START_TRACING RETRIES";
   }
 
   NOTREACHED();