Fixes #372 Add support for building Native Java images for the Java GenAI library

[ddobrin]

This commit contains the native image configuration work for the java-genai library: tracks 1.21.0-SNAPSHOT

• Native Image Reflection Configuration

• Added comprehensive reflection metadata for all 346 type classes in com.google.genai.types package
• Registered all AutoValue generated classes and their Builders
• Added reflection support for 43 main package classes including Models, ResponseStream, and other core API classes
• Total: ~10,242 lines of reflection configuration

• Test Infrastructure

• Created NativeImageReflectionTest.java to exercise builder types and ensure reflection metadata capture
• Added test methods for AutoValue builders and JSON deserialization

• Build Configuration

• Updated pom.xml with native-maven-plugin and native-tests profile
• Configured agent for native-image metadata generation
• Added agentlib configuration for test execution

• Native Image Metadata Files

• reflect-config.json - Comprehensive reflection metadata with allDeclaredMethods for all types
• jni-config.json - JNI access configuration
• proxy-config.json - Dynamic proxy configuration
• resource-config.json - Resource inclusion patterns
• serialization-config.json - Serialization support

• Scripts & Tooling

• Created shell scripts for generating reflection configurations automatically

This commit enables the java-genai library to work correctly in GraalVM native image applications by providing all necessary reflection, JNI, and resource metadata.

Test app to use the native image:
https://github.com/ddobrin/ai-native

[nireekshak]

Hi @ddobrin,
Thanks for your contributions!
We noticed that the checks have failed. Could you please review and update the PR so we can proceed further?
Appreciate your support on this.