Add flag com.example.android.aconfig.demo.flags.pc_test_2 to trunk_staging.

This change was automatically created by advancing the Gantry workflow at:
https://releasetracker.partner.android.com/changes/cv15qfi000001?build_unique_id=com.example.android.aconfig.demo.flags.pc_test_2-platform
Do not edit this file manually or revert this change - use the Gantry workflow to manage the state of this flag.

Bug: 336778457
Flag: com.example.android.aconfig.demo.flags.pc_test_2
Ignore-AOSP-First: AConfig change for future AOSP release
Change-Id: Ie8466726f20d27e8c2e6132591df05e4a712a1bb