Filter on availability signals.
.. attribute:: signal_type
Required. Type of signal to apply filter on.
If multiple [AvailabilityFilter][google.cloud.talent.v4beta1.A
vailabilityFilter] are provided, the default behavior is to OR
all filters, but if this field is set to true, this particular
[AvailabilityFilter][google.cloud.talent.v4beta1.AvailabilityF
ilter] will be AND'ed against other [AvailabilityFilter][googl
e.cloud.talent.v4beta1.AvailabilityFilter].