[WIP] Update processors module to follow style guide

[Copilot]

Plan to update processors module to follow docs/style-guide.md with minimal changes:

• Explore repository structure and identify processors module
• Review current code for style guide compliance
• Identify specific style guide violations
• Fix field visibility and final modifiers in FilteringLogRecordProcessor
• Add final modifiers to private fields in Interceptable*Exporter classes (already compliant)
• Replace manual service registration with @autoservice annotation
• Fix test compilation issues after making FilteringLogRecordProcessor final
• Remove unnecessary extra semicolons in test code
• Run spotlessApply to ensure formatting consistency
• Verify all changes with tests

Changes Made:

FilteringLogRecordProcessor.java

• Made class final per style guide for public non-internal classes
• Changed public fields to private final for proper encapsulation

EventToSpanEventBridgeComponentProvider.java

• Added @AutoService(ComponentProvider.class) annotation to replace manual service registration
• Added @SuppressWarnings("rawtypes") to handle generic service provider warning
• Removed manual service file as @autoservice generates it automatically

build.gradle.kts

• Added AutoService annotation processor and compile-only dependencies
• Added explanatory comment about AutoService usage

FilteringLogRecordProcessorTest.java

• Fixed test compilation by removing empty anonymous class body {}
• Cleaned up extra semicolons after field declarations

All tests pass and code formatting is applied according to the style guide.

Fixes #276.

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