chore: add test-runner-class, secrets and emu networking opts

[madisp]

Add forwards to the new options added in emulator-wtf/invoke#137.

[Copilot]

Pull Request Overview

This PR adds support for new command-line options that were introduced in emulator-wtf/invoke#137, specifically adding test runner configuration, secret environment variables, and emulator networking options.

• Adds test-runner-class input for specifying custom instrumentation runner classes
• Introduces secret-environment-variables for securely passing sensitive data to tests
• Adds four new emulator networking options: dns-server, dns-override, egress-tunnel, and egress-localhost-fwd-ip

Reviewed Changes

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

File	Description
action.yml	Adds new input definitions and forwards them to the underlying action
README.md	Documents the new inputs in the table format with descriptions

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