roll_commenter: Include count when listing changes

Change-Id: Ia7bdf9baf9faead0126f53dac4f651c7b4a622cd
Reviewed-on: https://pigweed-review.googlesource.com/c/infra/recipes/+/286826
Commit-Queue: Rob Mohr <mohrr@google.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
Reviewed-by: Wyatt Hepler <hepler@google.com>
diff --git a/recipes/roll_commenter.expected/new_roller.json b/recipes/roll_commenter.expected/new_roller.json
index c33dbb6..f265f34 100644
--- a/recipes/roll_commenter.expected/new_roller.json
+++ b/recipes/roll_commenter.expected/new_roller.json
@@ -3670,7 +3670,7 @@
     "cmd": [],
     "name": "newly_rolled",
     "~followup_annotations": [
-      "@@@STEP_SUMMARY_TEXT@['c000011000011000011000011000011000011000']@@@"
+      "@@@STEP_SUMMARY_TEXT@1: ['c000011000011000011000011000011000011000']@@@"
     ]
   },
   {
diff --git a/recipes/roll_commenter.expected/one_successful_comment.json b/recipes/roll_commenter.expected/one_successful_comment.json
index f8cc1d6..fa92841 100644
--- a/recipes/roll_commenter.expected/one_successful_comment.json
+++ b/recipes/roll_commenter.expected/one_successful_comment.json
@@ -3584,7 +3584,7 @@
     "cmd": [],
     "name": "newly_rolled",
     "~followup_annotations": [
-      "@@@STEP_SUMMARY_TEXT@['c000011000011000011000011000011000011000']@@@"
+      "@@@STEP_SUMMARY_TEXT@1: ['c000011000011000011000011000011000011000']@@@"
     ]
   },
   {
diff --git a/recipes/roll_commenter.expected/one_successful_comment_dry_run_suppress.json b/recipes/roll_commenter.expected/one_successful_comment_dry_run_suppress.json
index da920c4..59d3160 100644
--- a/recipes/roll_commenter.expected/one_successful_comment_dry_run_suppress.json
+++ b/recipes/roll_commenter.expected/one_successful_comment_dry_run_suppress.json
@@ -3670,7 +3670,7 @@
     "cmd": [],
     "name": "newly_rolled",
     "~followup_annotations": [
-      "@@@STEP_SUMMARY_TEXT@['c000011000011000011000011000011000011000']@@@"
+      "@@@STEP_SUMMARY_TEXT@1: ['c000011000011000011000011000011000011000']@@@"
     ]
   },
   {
diff --git a/recipes/roll_commenter.expected/two_successful_comments.json b/recipes/roll_commenter.expected/two_successful_comments.json
index fb76a86..e9e1239 100644
--- a/recipes/roll_commenter.expected/two_successful_comments.json
+++ b/recipes/roll_commenter.expected/two_successful_comments.json
@@ -3670,7 +3670,7 @@
     "cmd": [],
     "name": "newly_rolled",
     "~followup_annotations": [
-      "@@@STEP_SUMMARY_TEXT@['c000011000011000011000011000011000011000', 'c000010000010000010000010000010000010000']@@@"
+      "@@@STEP_SUMMARY_TEXT@2: ['c000011000011000011000011000011000011000', 'c000010000010000010000010000010000010000']@@@"
     ]
   },
   {
diff --git a/recipes/roll_commenter.py b/recipes/roll_commenter.py
index 5973991..755200d 100644
--- a/recipes/roll_commenter.py
+++ b/recipes/roll_commenter.py
@@ -283,7 +283,7 @@
             newly_rolled.append(revisions[i])
 
         pres = api.step.empty('newly_rolled').presentation
-        pres.step_summary_text = repr(newly_rolled)
+        pres.step_summary_text = f'{len(newly_rolled)}: {newly_rolled!r}'
 
         # This is awkward and not useful in MILO but useful in recipe testing.
         with api.step.nest('moved forward'):