[Feature] Add test coverage for Expo EAS app configuration caching

[EmmaYuan1015]

Description

The Expo EAS project configuration helpers currently lack dedicated test
coverage.

Tests should verify that getExpoEasProjectOwner,
getExpoEasProjectId, and getExpoEasProjectName correctly read values
from app.json and safely handle missing optional configuration.

The modification-time-based cache also needs coverage to ensure repeated
calls reuse the parsed configuration and changes to app.json invalidate
the cache.

Proposed tests

• Verify the EAS project owner, ID, and name are read from app.json
• Verify repeated getter calls reuse the cached configuration
• Verify the configuration is read again when the file modification time changes
• Verify missing optional Expo/EAS properties return null

Expected result

The Expo EAS configuration reading and caching behavior is protected
against regressions.

Dependency

This work depends on the Expo EAS app configuration refactor introduced
by refactor-expo-eas-app-config.