bump sdk_tag to 3.7.0-27.0.dev (for wildcards)

Change-Id: I3cb61289e337000fa949a4a7b68cce2b48e47f60
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/390623
Commit-Queue: Phil Quitslund <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>
Reviewed-by: Kallen Tu <[email protected]>
Auto-Submit: Phil Quitslund <[email protected]>
Reviewed-by: Alexander Thomas <[email protected]>

Author: pq

DEPS

@@ -50,7 +50,7 @@ vars = {
   # Checked-in SDK version. The checked-in SDK is a Dart SDK distribution
   # in a cipd package used to run Dart scripts in the build and test
   # infrastructure, which is automatically built on the release commits.
-  "sdk_tag": "git_revision:7e6469bd51d404916395a47b011d907d2c905121",
+  "sdk_tag": "git_revision:7fce3544047c41018b8c00b4453c0262f463dd74",
 
   # co19 is a cipd package automatically generated for each co19 commit.
   # Use tests/co19/update.sh to update this hash.