:keyword Union[bool, dict[str, Any]] availability_strategy:
        Enables an availability strategy by using cross-region request hedging.
        Can be True (use default values: threshold_ms=500, threshold_steps_ms=100),
        False (disable hedging)
        or a dict with keys ``threshold_ms`` and ``threshold_steps_ms`` to configure custom values.
        Default value is False (hedging disabled).

        :keyword Union[bool, dict[str, Any]] availability_strategy: Enables an availability strategy by using cross-region request hedging.
            Can be True (use client config if present, otherwise use default values: threshold_ms=500, threshold_steps_ms=100),
            False (disable hedging even if client has it enabled),
            or a dict with keys ``threshold_ms`` and ``threshold_steps_ms`` to override the client's configured availability strategy.
            If not provided, uses the client's configured strategy.