probeExtendedFeatureFlags
Builds a label=bool string reporting presence of each feature in EXTENDED_FEATURES (fingerprint, face/iris biometrics, NFC, BLE, USB host, StrongBox, etc.).
Privacy: PackageManager.hasSystemFeature requires no permission; the combined flags form part of the hardware fingerprint.
Return
Semicolon-separated label=true/false capability string.
Parameters
context
Context providing the package manager.