add internal remote config patch tool

[LukasPaczos]

Task/Issue URL: https://app.asana.com/1/137249556945/project/1208671518894266/task/1210708742763735

Description

Adds tooling to locally patch remote config. Read the details in the new README file in the diff.

Steps to test this PR

1. Create a privacy-config/privacy-config-internal/local-patch-file/test_patch.json file with this content:

[
  {
    "op": "replace",
    "path": "/features/aiChat/state",
    "value": "disabled"
  }
]

2. Create a privacy-config/privacy-config-internal/local.properties file with this content:

config_patches=privacy-config/privacy-config-internal/local-config-patches/test_patch.json

3. Clean install the app.
4. Verify Duck.ai is disabled and that Settings -> Duck.ai is gone.
5. Update the patch file to:

[
  {
    "op": "replace",
    "path": "/version",
    "value": "2752244802866"
  },
  {
    "op": "remove",
    "path": "/features/aiChat/hash"
  }
]

6. Relaunch the app (without clean installing it). This will download the production config and force update the feature because of the bumped version number and mismatching hash.
7. Verify Duck.ai is enabled and that Settings -> Duck.ai is available.
8. Update the test_patch.json to disable Duck.ai again and bump version:

[
  {
    "op": "replace",
    "path": "/features/aiChat/state",
    "value": "disabled"
  },
  {
    "op": "remove",
    "path": "/features/aiChat/hash"
  },
  {
    "op": "replace",
    "path": "/version",
    "value": "3752244802866"
  }
]

9. Relaunch the app (without clean installing it).
10. Verify Duck.ai is disabled and that Settings -> Duck.ai is gone.

[LukasPaczos]

All interceptors are currently added in default order, sorted by class name. If I assign a low priority to this interceptor without changing the others, it would run first, since it would be the only one with a defined priority. I tried giving all plugins the same priority (to preserve class name sorting as PriorityKey docs suggest) and setting this interceptor last, but the build fails due to duplicate priority keys, despite what the docs say.

I don’t want to risk changing any production behavior, so it’s fine if this interceptor doesn’t run last for now. If it ever becomes a problem, we can revisit.

[Copilot]

Pull Request Overview

This PR adds local remote config patching tooling for development builds, allowing developers to override production remote config values locally without server deployments. The implementation uses JSON Patch format to apply runtime modifications to privacy config responses.

Key changes:

• Introduces JSON patch-based remote config modification system for internal builds
• Adds flexible configuration through command-line parameters or local.properties files
• Implements asset copying and build-time validation for patch files

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
versions.properties	Adds zjsonpatch library dependency for JSON Patch operations
DevPrivacyConfigPatchApiInterceptor.kt	New interceptor that applies JSON patches to privacy config API responses
build.gradle	Implements patch file discovery, copying, and build configuration logic
README.md	Documents the patching system usage and configuration options
.gitignore	Excludes local patch files and configuration from version control

Comments suppressed due to low confidence (1)

[Copilot]

This line should use the request parameter instead of chain.request() since the request was already extracted on line 46. Using chain.request() creates a new request object unnecessarily.

Suggested change

	return chain.proceed(chain.request())
	return chain.proceed(request)

[Copilot]

Adding the build directory path to source sets during configuration time can cause issues with Gradle's build cache and configuration caching. Consider using a different approach such as configuring this in the copyConfigPatches task or using a pre-existing assets directory.

Suggested change

	afterEvaluate {
	// Moved to afterEvaluate to avoid configuration time issues with Gradle caching
	afterEvaluate {
	// Add generated configPatches assets directory to source sets at execution time
	android.sourceSets.main.assets.srcDirs += layout.buildDirectory.dir("generated/assets/configPatches").get().asFile.path

[joshliebe]

First testing step should be local-config-patches instead of local-patch-file but works as expected! Nice one 🙂