Add emoji to build server related output

Bug: 404503040
Change-Id: Ife7d3d336bfbfb6513a2bb805f4b23d48e1c61d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6368643
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Auto-Submit: Mohamed Heikal <mheikal@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>

android_build_server_helper.py

@@ -38,7 +38,7 @@ def _set_signal_handler(local_dev_server_path, build_id):
         global _is_canceled
         _is_canceled = True
         # Cancel the pending build tasks if user CTRL+c early.
-        print('Canceling pending build_server tasks', file=sys.stderr)
+        print('🛑 Canceling pending build_server tasks', file=sys.stderr)
         subprocess.run([local_dev_server_path, '--cancel-build', build_id])
         original_sigint_handler(signum, frame)