initialise
Initialise the MobileCredentialHolder SDK.
This function requires user authentication to execute successfully. If a suitable user authentication mechanism is not setup on the device OR authentication fails for some reason, suitable errors will be thrown.
An important behaviour to note is that after initialising the SDK for the first time, if the user disables user authentication on their device entirely and then re-enables it, they will no longer be able to initialise the SDK. A HolderException.UserAuthenticationUnrecoverableKeyException will be thrown as the decryption key stored in the android key store used to decrypt the storage will no longer be accessible. The instance must be deleted using the destroy API and re-initialised.
Parameters
Android activity used to perform user authentication
OPTIONAL Used to identify the instance to configure for the SDK initialisation This will load all certificates and credentials unique to this instance. If instance is empty, the default instance will be used.