[Android] ReactRootProjectPlugin drops :app:preBuild -> library preBuild dependency under --configure-on-demand, breaking codegen before CMake

Description

ReactRootProjectPlugin makes :app:preBuild depend on every library's preBuild so that library codegen runs before the app's CMake configure:

project.gradle.projectsEvaluated {
  val appProject = project.rootProject.subprojects.find { it.name == "app" }
  val appPreBuild = appProject?.tasks?.findByName("preBuild")
  if (appPreBuild != null) {
    val otherPreBuildTasks =
        project.rootProject.subprojects
            .filter { it != appProject }
            .mapNotNull { it.tasks.findByName("preBuild") }
    appPreBuild.dependsOn(otherPreBuildTasks)
  }
}

When Gradle runs with --configure-on-demand (Expo CLI passes it unconditionally in expo run:android), a library project that has not been evaluated by the time projectsEvaluated fires has no preBuild task yet, so findByName returns null and the dependency is silently dropped. The app's configureCMake<Variant> then runs before that library's generateCodegenArtifactsFromSchema, and the autolinking CMake file fails with:

CMake Error at android/app/build/generated/autolinking/src/main/jni/Android-autolinking.cmake:19 (add_subdirectory):
  add_subdirectory given source
  ".../node_modules/react-native-sherpa-onnx/android/build/generated/source/codegen/jni/"
  which is not an existing directory.
CMake Error at .../ReactAndroid/cmake-utils/ReactNative-application.cmake:97 (target_link_libraries):
  Cannot specify link libraries for target "react_codegen_SherpaOnnxSpec"
  which is not built by this project.

Which libraries are affected depends on evaluation order, so it looks flaky per project. In my project @stripe/stripe-react-native (also a codegen TurboModule library) happened to be evaluated in time and worked, while react-native-sherpa-onnx was not. The same failure was reported independently against that library (XDcobra/react-native-sherpa-onnx#63) and closed as not reproducible, which fits an ordering-dependent bug.

Running the identical build without --configure-on-demand (./gradlew :app:assembleDebug -PreactNativeArchitectures=arm64-v8a) succeeds; the task log shows :react-native-sherpa-onnx:generateCodegenArtifactsFromSchema → :app:preBuild → :app:configureCMakeDebug[arm64-v8a].

Workaround (verified): in the app's build.gradle, add an explicit task-path dependency, which forces on-demand configuration of that project:

preBuild.dependsOn(':react-native-sherpa-onnx:preBuild')

A robust fix would be to wire the dependency per subproject as each one is evaluated (e.g. subproject.afterEvaluate { appPreBuild.dependsOn(subproject.tasks.named("preBuild")) }, or dependsOn("${subproject.path}:preBuild") by task path) instead of snapshotting subprojects at projectsEvaluated.

Steps to reproduce

1. npx create-expo-app repro && cd repro
2. npx expo install react-native-sherpa-onnx @dr.pogodin/react-native-fs (any third-party library with codegenConfig and a JNI target that Gradle happens to evaluate late)
3. npx expo run:android (Expo CLI runs Gradle with --configure-on-demand)
4. Build fails in :app:configureCMakeDebug[<abi>] as above.
5. cd android && ./gradlew :app:assembleDebug succeeds.

React Native Version

0.86.0

Affected Platforms

Build - Android

Output of npx @react-native-community/cli info

System:
  OS: macOS 26.6.2
  CPU: (14) arm64 Apple M4 Pro
Binaries:
  Node: 24.12.0
  npm: 11.6.2
  Watchman: Not Found
Managers:
  CocoaPods: 1.17.0
IDEs:
  Android Studio: 2025.3
  Xcode: 26.2/17C52
Languages:
  Java: 17.0.12
Expo SDK 57 (expo 57.0.8), Gradle 9.3.1, AGP as shipped with RN 0.86.0, NDK 27.1.12297006, CMake 3.22.1

Stacktrace or Logs

> Task :stripe_stripe-react-native:generateCodegenArtifactsFromSchema
> Task :app:preBuild
...
> Task :react-native-sherpa-onnx:downloadNativeLibsIfNeeded
> Task :app:configureCMakeDebug[arm64-v8a] FAILED
(no :react-native-sherpa-onnx:generateCodegenArtifactsFromSchema before the failure)

Execution failed for task ':app:configureCMakeDebug[arm64-v8a]'.
> [CXX1429] error when building with cmake using .../ReactAndroid/cmake-utils/default-app-setup/CMakeLists.txt
  CMake Error at .../Android-autolinking.cmake:19 (add_subdirectory):
    add_subdirectory given source ".../react-native-sherpa-onnx/android/build/generated/source/codegen/jni/" which is not an existing directory.

MANDATORY Reproducer

Steps above (create-expo-app + react-native-sherpa-onnx + expo run:android). The failure depends on Gradle's on-demand evaluation order, so the library that gets skipped may differ by project.

Screenshots and Videos

N/A

首先定位 ReactRootProjectPlugin，并跟踪 projectsEvaluated 如何发现库的 preBuild 任务。使用 Expo 和 react-native-sherpa-onnx 的必需步骤重现问题，然后比较使用 --configure-on-demand 与普通模式时 Gradle 任务的顺序。当库的 codegen 在 app configureCMake 之前运行，并且 autolinking 的 CMake 生成成功时，即表示完成。