Add flag com.android.bluetooth.flags.merge_call_with_held_conference to trunk_staging. This change was automatically created by advancing the Gantry workflow at: https://releasetracker.partner.android.com/changes/bv730hq000001?build_unique_id=com.android.bluetooth.flags.merge_call_with_held_conference-platform Do not edit this file manually or revert this change - use the Gantry workflow to manage the state of this flag. Bug: 397374535 Flag: com.android.bluetooth.flags.merge_call_with_held_conference Ignore-AOSP-First: AConfig change for future AOSP release Change-Id: Ibc01657cab16b108f74ca9dc31a855e17974636a