Bring dart_style 1.2.7 into the SDK repo.

This just has one change, a fix to how adjacent strings inside "=>"
functions are indented.

Change-Id: I457ea308101be9fb5acc4257e47360635a2b97e0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/98746
Commit-Queue: Kevin Moore <kevmoo@google.com>
Reviewed-by: Kevin Moore <kevmoo@google.com>
diff --git a/DEPS b/DEPS
index 12a540e..5c76e5a 100644
--- a/DEPS
+++ b/DEPS
@@ -79,7 +79,7 @@
   #     and land the review.
   #
   # For more details, see https://github.com/dart-lang/sdk/issues/30164
-  "dart_style_tag": "1.2.6",  # Please see the note above before updating.
+  "dart_style_tag": "1.2.7",  # Please see the note above before updating.
 
   "dartdoc_tag" : "v0.28.2",
   "fixnum_tag": "0.10.9",