Export SUPPORT_BLUETOOTH_QUALITY_REPORT_V6

This flag is for API, it must be exported or CTS won't be able to call
it.

Bug: 364517559
Fix: 380709792
Fix: 380709791
Fix: 380709747
Flag: com.android.bluetooth.flags.support_bluetooth_quality_report_v6
Test: m CtsBluetoothTestCases
Change-Id: I95b011c9261695c6549f96c9a5f1db3fb4f38e33