Roll Flutter Engine from 394554bd1630 to 8c7ce6ddde0f (2 revisions) (#132921)

https://github.com/flutter/engine/compare/394554bd1630...8c7ce6ddde0f

2023-08-20 skia-flutter-autoroll@skia.org Roll Skia from 4f6b9d08b6d1 to d2369dac4a1d (6 revisions) (flutter/engine#44883)
2023-08-20 bdero@google.com [Impeller] Fix clip management for DrawPicture. (flutter/engine#44835)

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://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

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

bin/internal/engine.version

-394554bd1630be06983c8e367d9efc4cd2195040
+8c7ce6ddde0fca50aa59dbd49e887d3c892473a3