Switch `cronet_http` to use jnigen #765

Job	Run time
mono_repo self validate	27s
analyze_and_format; Dart 2.19.0; PKG: pkgs/http_client_conformance_tests; `dart analyze --fatal-i...	39s
analyze_and_format; Dart 3.0.0; PKG: pkgs/http; `dart analyze --fatal-infos`	29s
analyze_and_format; Dart dev; PKGS: pkgs/http, pkgs/http_client_conformance_tests; `dart analyze ...	30s
analyze_and_format; Dart dev; PKGS: pkgs/http, pkgs/http_client_conformance_tests; `dart format -...	33s
unit_test; Dart 3.0.0; PKG: pkgs/http; `dart test --platform chrome`	3m 12s
unit_test; Dart 3.0.0; PKG: pkgs/http; `dart test --platform vm`	54s
unit_test; Dart dev; PKG: pkgs/http; `dart run --define=no_default_http_client=true test/no_defau...	21s
unit_test; Dart 3.0.0; PKG: pkgs/http; `dart run --define=no_default_http_client=true test/no_def...	29s
unit_test; Dart dev; PKG: pkgs/http; `dart test --platform chrome`	2m 20s
unit_test; Dart dev; PKG: pkgs/http; `dart test --platform vm`	53s
	10m 47s

Provide feedback