Set longer default retry, backoff and attempt count for Consul Template

[mikenomitch]

Proposal

If a user does not override retry attempts, max backoff, or default backoff values on Consul Template, they get only 12 retry attempts and only a few minutes of retry time before tasks start failing (See #13019 for a failure issue). This means that if Vault or Consul goes down for over a few minutes (or a connection is bad) then all tasks on the Nomad cluster can go down.

We should default these times to greater numbers to they have more protection in the case of long outages.

This should be done for both consul and vault.

Use-cases

This would allow Nomad tasks to be more resilient if Vault or Consul go down.

[github-actions]

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