DefaultDeviceIdentifier

The default implementation of DeviceIdentifier that uses the Android KeyStore to generate a persistent device identifier.

This implementation:

• Creates an RSA key pair in the Android KeyStore the first time it's accessed

• Uses the public key as the basis for a device identifier

• Applies SHA-256 hashing to the key data and converts it to a hex string

• Caches the identifier for efficient subsequent access

Note: The identifier will change if the device is factory reset or if the key is explicitly removed from the KeyStore.