Pause and wake requests do not wait in a queue during an outage

While Runtime cannot carry out pauses and wakes, POST /v1/sandboxes/{id}:pause, :wake, :restart and automatic wakes return 503 api_unavailable and leave the sandbox unchanged; retry after Retry-After. A pause that Runtime accepted but did not start within 5 minutes is withdrawn and the sandbox returns to running; a wake that did not start within 5 minutes returns the sandbox to paused. Previously such a request could leave a sandbox pausing or waking for hours, and then take effect hours later.