Migrate tsmon protos to proto3

common/tsmon/ts_mon_proto/acquisition_network_device.proto

Index: common/tsmon/ts_mon_proto/acquisition_network_device.proto
diff --git a/common/tsmon/ts_mon_proto/acquisition_network_device.proto b/common/tsmon/ts_mon_proto/acquisition_network_device.proto
index b1f8657754e803c2060b02e217280121f241fd24..8fb619bcc6a4267d1c0dd437935796564fd95b81 100644
--- a/common/tsmon/ts_mon_proto/acquisition_network_device.proto
+++ b/common/tsmon/ts_mon_proto/acquisition_network_device.proto
@@ -4,18 +4,16 @@
 
 // Copied from https://chromium.googlesource.com/infra/infra/+/master/infra_libs/ts_mon/protos/
 
-syntax = "proto2";
+syntax = "proto3";
 
 package ts_mon.proto;
 
 message NetworkDevice {
-  enum TypeId { MESSAGE_TYPE_ID = 34049749; };
-
-  optional bool alertable = 101;
-  optional string realm = 102;
-  optional string metro = 104;
-  optional string role = 105;
-  optional string hostname = 106;
-  optional string hostgroup = 108;
+  bool alertable = 101;
+  string realm = 102;
+  string metro = 104;
+  string role = 105;
+  string hostname = 106;
+  string hostgroup = 108;
 }