Name of the default scheme to use (must match a scheme's name).
Registered authentication schemes.
OptionaltryOptional ordered authentication fallback.
By default, only defaultScheme is attempted. Set to 'all' to try
every registered scheme in registration order, or pass scheme names to
try a specific ordered subset.
Authentication configuration passed to
ServerBuilder.useAuthentication().At least one scheme must be listed. The
defaultSchemename must match one of the registered schemenamevalues — it is used when no specific scheme is requested.