Backport of fix(connect envoy): set initial_fetch_timeout to wait for initial xDS… into release/1.14.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #17317 to be assessed for backporting due to the inclusion of the label backport/1.14.

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The person who merged in the original PR is:
@DanStough
This person should manually cherry-pick the original PR into a new backport PR,
and close this one when the manual backport PR is merged in.

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The below text is copied from the body of the original PR.

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Description

Consul updates for #17283. Consul dataplane updates to follow.

This changes the time Envoy waits for the initial xDS configuration from the default (15s) to indefinitely. This prevents Envoy from starting with only a partial list of listeners/clusters.

Testing & Reproduction steps

Goldenfile tests have been updated since this affects Envoy's bootstrap configuration.

PR Checklist

• updated test coverage
• external facing docs updated
• appropriate backport labels added
• not a security concern

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Overview of commits

• 530d192 - 13f9965

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[github-team-consul-core-pr-approver]

Auto approved Consul Bot automated PR

[DanStough]

Opened up a manual version here: #17372