probeDrmId
Reads a DRM device-unique id (e.g. Widevine) via MediaDrm and returns it hashed as hex.
Privacy: high — PROPERTY_DEVICE_UNIQUE_ID is a stable, hardware-backed identifier that can persistently track a device. The value is hex-encoded here; callers surface it as a strong fingerprint signal. No runtime permission gates this API, which is precisely why it is privacy-sensitive.
Return
Hex-encoded device id, or null if the scheme/property is unavailable.
Parameters
uuid
DRM scheme UUID (e.g. Widevine) to open.