Create workflow to build Android LeapChat

[linmx0130]

Create the E2E test flow for Android LeapChat example app. Changes are

1. A new button in the UI to control whether to use tools in the chat.
2. An E2E test case with 2 turns of chat user interactions.
3. A new workflow to run the test on Google Firebase Test Lab.

[Copilot]

Pull Request Overview

This PR creates a comprehensive CI/CD workflow for building and testing the Android LeapChat application. It introduces test automation capabilities with Firebase Test Lab integration and adds tool functionality features.

• Adds GitHub Actions workflow for automated building and end-to-end testing
• Implements UI testing framework with test tags and E2E test cases
• Introduces tool toggle functionality with conditional function registration

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
.github/workflows/android-leap-chat-test.yml	New CI workflow for building and testing Android app on Firebase Test Lab
Android/LeapChat/app/src/androidTest/java/ai/liquid/leapchat/MainActivityTest.kt	New E2E test class for chat functionality validation
Android/LeapChat/app/src/main/java/ai/liquid/leapchat/MainActivity.kt	Added tool toggle UI, test tags, and model configuration changes
Android/LeapChat/app/src/main/java/ai/liquid/leapchat/views/AssistantMessage.kt	Added test tags for UI testing
Android/LeapChat/app/src/main/res/values/strings.xml	Added strings for tool toggle button labels
Android/LeapChat/gradle/libs.versions.toml	Updated Leap SDK version from 0.4.0 to 0.5.0

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[Copilot]

The service account key is written to a temporary file without proper cleanup. Consider using stdin for authentication or ensure the file is securely deleted after use.

Suggested change

	gcloud auth activate-service-account --key-file=/tmp/service_account.json
	gcloud auth activate-service-account --key-file=/tmp/service_account.json
	rm /tmp/service_account.json

[linmx0130]

Not necessary as the environment will be cleaned up by Github Action runners.

[Copilot]

[nitpick] Switching from lfm2-1.2b to lfm2-350m represents a significant reduction in model size (1.2B to 350M parameters). While this improves performance and reduces resource usage, ensure this change aligns with the required model capabilities for the application.

Suggested change

	const val MODEL_SLUG = "lfm2-350m"
	const val QUANTIZATION_SLUG = "lfm2-350m-20250710-8da4w"
	/**
	* Model slug for LeapChat. Default is "lfm2-350m" (350M parameters).
	* Note: Switching from a larger model (e.g., "lfm2-1.2b") to "lfm2-350m" reduces resource usage
	* but may impact language understanding and generation quality. Ensure this aligns with your application's needs.
	* To use a different model, set the value via configuration or environment variable if supported.
	*/
	val MODEL_SLUG: String = System.getenv("LEAPCHAT_MODEL_SLUG") ?: "lfm2-350m"
	/**
	* Quantization slug for the selected model.
	* Update this value if you change the model slug.
	*/
	val QUANTIZATION_SLUG: String = System.getenv("LEAPCHAT_QUANTIZATION_SLUG") ?: "lfm2-350m-20250710-8da4w"