Adding flag com.android.server.am.oomadjuster_cached_app_tiers to trunk_staging.

This change was automatically created by advancing the Gantry workflow at:
https://releasetracker.partner.android.com/changes/ceqfkri000001?build_unique_id=android_platform_system_performance
Do not edit this file manually or revert this change - use the Gantry workflow to manage the state of this flag.

Bug: 369893532
Change-Id: I3ed21bd1aa852bf1a7b8be6ffd8f74f3076e959a
Flag: com.android.server.am.oomadjuster_cached_app_tiers
Ignore-AOSP-First: AConfig change for future AOSP release