In the very common case where provider configuration does not change, during preview we were calling `Configure` on the cloud provider twice - once for the "old" configuration, and once for the "new" configuration.
This is not necessary, and we can just avoid using the new provider when configuration has not changed, since we will have configured the old provider very early so if we can use that we should.
Note that this technically doesn't prevent the second call to `Configure` from being made, but it prevents us from ever waiting on it. We may want to go further and avoid even calling `Configure` on the provider in this case.
Part of #3671.
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