Roll Flutter Engine from 07f7532ecd29 to 20638b75c8c4 (2 revisions) (#146962)

https://github.com/flutter/engine/compare/07f7532ecd29...20638b75c8c4

2024-04-17 skia-flutter-autoroll@skia.org Roll Skia from a3a016537a8c to d221c1591d59 (2 revisions) (flutter/engine#52210)
2024-04-17 flar@google.com DisplayList tracks maximum render op depths (flutter/engine#52070)

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
diff --git a/bin/internal/engine.version b/bin/internal/engine.version
index c922d78..91775f1 100644
--- a/bin/internal/engine.version
+++ b/bin/internal/engine.version
@@ -1 +1 @@
-07f7532ecd29a0633826e900df62a89242440b91
+20638b75c8c4ab2d41f1cff66f15281ff200a193