[shard_util_v2] Fix format of led -real-build argument

The format project/bucket/builder works for buckets containing
a period, but the format luci.project.bucket:builder does not.

Change-Id: I0e4635d5b999d2ffa59dbe3c8ee534170d392993
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/37261
Commit-Queue: William Hesse <whesse@google.com>
Reviewed-by: Yusuf Mohsinally <mohsinally@google.com>
diff --git a/recipe_modules/shard_util_v2/api.py b/recipe_modules/shard_util_v2/api.py
index 1ea5162..90e1ec6 100644
--- a/recipe_modules/shard_util_v2/api.py
+++ b/recipe_modules/shard_util_v2/api.py
@@ -209,7 +209,7 @@
       led_data = self.m.led(
           'get-builder',
           '-real-build',
-          'luci.%s.%s:%s' % (parent.project, parent.bucket, builder_name),
+          '%s/%s/%s' % (parent.project, parent.bucket, builder_name),
       )
       edit_args = []
       for k, v in sorted(drone_properties.items()):
diff --git a/recipe_modules/shard_util_v2/examples/full.expected/presubmit_led.json b/recipe_modules/shard_util_v2/examples/full.expected/presubmit_led.json
index 6c81783..5f190dd 100644
--- a/recipe_modules/shard_util_v2/examples/full.expected/presubmit_led.json
+++ b/recipe_modules/shard_util_v2/examples/full.expected/presubmit_led.json
@@ -8,7 +8,7 @@
       "led",
       "get-builder",
       "-real-build",
-      "luci.proj.try:custom drone builder-try"
+      "proj/try/custom drone builder-try"
     ],
     "luci_context": {
       "realm": {
@@ -1460,7 +1460,7 @@
       "led",
       "get-builder",
       "-real-build",
-      "luci.proj.try:Linux Engine Drone-try"
+      "proj/try/Linux Engine Drone-try"
     ],
     "luci_context": {
       "realm": {