Roll Flutter Engine from 4878f1c9ed1c to a63841d0c64b (8 revisions) (#159057)

4878f1c9ed...a63841d0c6

2024-11-18 chris@bracken.jp iOS: Clean up @synthesize directives / ivars
(flutter/engine#56665)
2024-11-17 skia-flutter-autoroll@skia.org Roll Skia from 4708534db2e7 to
452208ce96aa (1 revision) (flutter/engine#56664)
2024-11-17 chris@bracken.jp iOS: Extract constant for
CADisableMinimumFrameDurationOnPhone (flutter/engine#56659)
2024-11-17 chris@bracken.jp iOS: Eliminate unnecessary use of
NSClassFromString (flutter/engine#56660)
2024-11-17 chris@bracken.jp iOS: Eliminate unnecessary bridged retain
casts (flutter/engine#56662)
2024-11-17 chris@bracken.jp iOS,macOS: Fix string constant declarations
(flutter/engine#56661)
2024-11-17 chris@bracken.jp iOS: Make FlutterViewController.engine a
strong ref (flutter/engine#56663)
2024-11-17 chris@bracken.jp iOS: Clean up uses of string literal
constants (flutter/engine#56658)

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 jimgraham@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

@@ -1 +1 @@
-4878f1c9ed1cebbc19cab7133f99cc904e65ef0e
+a63841d0c64bfd2b91fe383a4c6859c60044ac68