A policy that specifies how Cloud Pub/Sub retries message delivery.
Retry delay will be exponential based on provided minimum and maximum
backoffs. https://en.wikipedia.org/wiki/Exponential_backoff.
RetryPolicy will be triggered on NACKs or acknowledgement deadline
exceeded events for a given message. Retry Policy is implemented on a
best effort basis. At times, the delay between consecutive deliveries
may not match the configuration. That is, delay can be more or less
than configured backoff.
.. attribute:: minimum_backoff
The minimum delay between consecutive deliveries of a given
message. Value should be between 0 and 600 seconds. Defaults
to 10 seconds.
