[cronet_http] Upgrade jni and jnigen to 0.14.2

[HosseinYousefi]

• When migrating to the new declarative plugin style the repositories were accidentally removed from example/android/build.gradle, adding those back for jnigen to work again.
• Upgraded jni and jnigen to 0.14.2 and regenerated the bindings.
• Fixed the code that now is generated in a null-safe way.

@brianquinlan you may want to take a closer look at my changes here because I only added !s where it was previously assumed that the resulting JObject is non-null.

Another change I had to make was to make all of the method parameter types of UrlRequestCallbackProxy nullable.

As I wrote in the comments:

// Due to a bug (https://github.com/dart-lang/native/issues/2421) where JNIgen
// does not synchronize the nullabilities across the class hierarchy and the
// fact that UrlRequest.Callback is a Java class with no nullability
// annotations, generating both `UrlRequestCallbackProxy` and
// `UrlRequest.Callback` together with different nullabilities causes the
// super method to have a looser type for parameters which is a Dart compilation
// error. 
// That is why all of the parameters of this class are defined as nullable to
// match `UrlRequest.Callback` while in reality only `onFailed`'s `info`
// parameter is nullable as specified in the cronet source code:
// https://source.chromium.org/chromium/chromium/src/+/main:components/cronet/android/api/src/org/chromium/net/UrlRequest.java;l=232

[github-actions]

Package publishing

Package	Version	Status	Publish tag (post-merge)
package:cronet_http	1.4.0-wip	WIP (no publish necessary)
package:cupertino_http	2.3.0-wip	WIP (no publish necessary)
package:http	1.5.0-beta.2	already published at pub.dev
package:http2	3.0.0	ready to publish	http2-v3.0.0
package:http_multi_server	3.2.2	already published at pub.dev
package:http_parser	4.1.2	already published at pub.dev
package:http_profile	0.1.1-wip	WIP (no publish necessary)
package:ok_http	0.1.1-wip	WIP (no publish necessary)
package:web_socket	1.0.1	already published at pub.dev
package:web_socket_channel	3.0.3	already published at pub.dev

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

[github-actions]

PR Health

Breaking changes ⚠️

Package	Change	Current Version	New Version	Needed Version	Looking good?
cronet_http	Breaking	1.3.4	1.4.0-wip	2.0.0 Got "1.4.0-wip" expected >= "2.0.0" (breaking changes)	⚠️

This check can be disabled by tagging the PR with skip-breaking-check.

Changelog Entry ✔️

Package	Changed Files

Changes to files need to be accounted for in their respective changelogs.

Coverage ⚠️

File	Coverage
pkgs/cronet_http/lib/src/cronet_client.dart	💔 Not covered
pkgs/cronet_http/lib/src/jni/jni_bindings.dart	💔 Not covered

This check for test coverage is informational (issues shown here will not fail the PR).

This check can be disabled by tagging the PR with skip-coverage-check.

API leaks ✔️

The following packages contain symbols visible in the public API, but not exported by the library. Export these symbols or remove them from your publicly visible API.

Package	Leaked API symbols

License Headers ✔️

// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

Files
no missing headers

All source files should start with a license header.

Unrelated files missing license headers

Files
pkgs/http/example/main.dart

[brianquinlan]

Thanks so much for doing this!