Flag changes for checking invalid discovery database

Bug: 356201480
Bug: 315241296
Flag: com.android.bluetooths.flag.btsec_check_valid_discovery_database
Test: m libbluetooth
Tag: #security
Ignore-AOSP-First: Security
Change-Id: Id67a4bfb6761b3cfad5b52775a5bb9a3d765a3c3