Support --dry_run option in edit monitor

If --dry_run option is set, edit monitor runs without actually sending
the edit logs to clearcut

Test: atest edit_monitor_test
bug: 365617369
Change-Id: I793d9b0a2e16ffa70fe03d1d3f53d676a1d86cf3
diff --git a/tools/edit_monitor/edit_monitor.py b/tools/edit_monitor/edit_monitor.py
index 31115d4..ab528e8 100644
--- a/tools/edit_monitor/edit_monitor.py
+++ b/tools/edit_monitor/edit_monitor.py
@@ -43,6 +43,7 @@
       path: str,
       flush_interval_sec: int,
       single_events_size_threshold: int,
+      is_dry_run: bool = False,
       cclient: clearcut_client.Clearcut | None = None,
   ):
 
@@ -50,6 +51,7 @@
     self.root_monitoring_path = path
     self.flush_interval_sec = flush_interval_sec
     self.single_events_size_threshold = single_events_size_threshold
+    self.is_dry_run = is_dry_run
     self.cclient = cclient or clearcut_client.Clearcut(LOG_SOURCE)
 
     self.user_name = getpass.getuser()
@@ -164,6 +166,10 @@
       )
       edit_events = [(aggregated_event_proto, aggregated_event_time)]
 
+    if self.is_dry_run:
+      logging.info("Sent %d edit events in dry run.", len(edit_events))
+      return
+
     for event_proto, event_time in edit_events:
       log_event = clientanalytics_pb2.LogEvent(
           event_time_ms=int(event_time * 1000),
@@ -176,6 +182,7 @@
 
 def start(
     path: str,
+    is_dry_run: bool = False,
     flush_interval_sec: int = DEFAULT_FLUSH_INTERVAL_SECONDS,
     single_events_size_threshold: int = DEFAULT_SINGLE_EVENTS_SIZE_THRESHOLD,
     cclient: clearcut_client.Clearcut | None = None,
@@ -192,7 +199,7 @@
     conn: the sender of the pipe to communicate with the deamon manager.
   """
   event_handler = ClearcutEventHandler(
-      path, flush_interval_sec, single_events_size_threshold, cclient)
+      path, flush_interval_sec, single_events_size_threshold, is_dry_run, cclient)
   observer = Observer()
 
   logging.info("Starting observer on path %s.", path)