Set appropriate default setting for kernel bytecode in D27 Dart sdk release

[a-siva]

kernel bytecode is currently turned on by default in the Dart SDK and Flutter for the AOT pipeline but turned off in Google3 both in Dart SDK and Flutter.

It has not yet been turned on by default in the JIT pipeline.

For the D27 and Flutter 1.12 release this setting shoujld be consistent across both Dart SDK and Flutter.

[a-siva]

bytecode has been turned off by default consistently in AOT/JIT and G3 for the D27 release
https://dart-review.googlesource.com/c/sdk/+/124469