Roll Flutter Engine from 215d55f4f82d to 0849250a1419 (2 revisions) (#143425)

https://github.com/flutter/engine/compare/215d55f4f82d...0849250a1419

2024-02-14 30870216+gaaclarke@users.noreply.github.com [Impeller] replaces golden file count with a golden diff file (flutter/engine#50621)
2024-02-14 bdero@google.com [Impeller] Migrate all ColorSourceContents to use a shared rendering routine. (flutter/engine#50261)

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC jsimmons@google.com,rmistry@google.com,zra@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in Flutter: https://github.com/flutter/flutter/issues/new/choose

To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622

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

bin/internal/engine.version

-215d55f4f82df91d5c8080bd5140ba929013feda
+0849250a141981bcd4f948cd392ba725ec948ef9