[ads] Double delay for backoff timers

[tmancey]

Description

Following server requests are affected:

• Catalog (catalogs would have been fetched every 2 to 6 hours, rather than the expected 1 to 3 hours)
• Issuers (issuers would have been fetched every 2 to 6 hours, rather than the expected 1 to 3 hours)
• Confirmation token redemption (only affects retries)
• Refill confirmation tokens (only affects retries)
• Geo targeting (subdivision would have been fetched every 1 to 3 days, rather than the expected 0.5 to 1.5 days)

This does not only affect exponential backoffs, it also affects the initial delay when starting the above timers to fetch after a period of time.