[Java] Fetch stream configs with variable duration, especially if call fails.

When we initialize the Metrics Platform library from our client code, we give it a generously long delay interval for fetching stream configurations (12 hours), since these are highly unlikely to change within the course of a single day.

However, if the call to fetch the configurations fails (e.g. due to poor network conditions), it means it will need to wait another 12 hours before trying the call again. And if this call fails when the library is first initialized, it means the library will be sitting without configurations for the next 12 hours.

Let's update the Runnable that fetches the stream configurations to have a variable delay, conditional on the outcome of the network call. If the call succeeds, the Runnable will reschedule itself with the default interval. But if it fails, it will reschedule itself with a delay of 1 minute.

Bug: T365179