Roll engine e859296b71de..6a9041853c4b (4 commits) (#25643)

https://github.com/flutter/engine/compare/e859296b71de...6a9041853c4b

git log e859296b71de..6a9041853c4b --no-merges --oneline
6a9041853 [License] Assert license filename is non-null, non-empty (flutter/engine#7270)
72aa37842 [License] Eliminate duplicate case in switch (flutter/engine#7269)
74af4429a Mark all unreassigned locals final in license tool (flutter/engine#7267)
0310e910d Roll src/third_party/skia 44539be30ef8..b03e024a4034 (7 commits) (flutter/engine#7268)

The AutoRoll server is located here: https://autoroll.skia.org/r/flutter-engine-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff (liyuqian@google.com), and stop
the roller if necessary.

bin/internal/engine.version

-e859296b71def257f021ff8bd225e82209558cea
+6a9041853c4bb9a878f4962ad3f4bda93c06ed68