[IP Protection] Add retries for DNS errors

From comments elsewhere in the code, on network changes during a DNS resolution, a DNS error will occur instead of a network change error. In
these cases, we should also retry.

This might help cut down on the number of "INVALID_ARGUMENT:
GetInitialDataRequest failed: invalid response" errors we are seeing.
For more info on that, see: b/392707755#comment6

Bug: b/392707755
Change-Id: I58d147057202a7ce707bb69422b4e6a8c974fe84
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6214076
Commit-Queue: Andrew Williams <awillia@chromium.org>
Reviewed-by: Ciara McMullin <ciaramcmullin@google.com>
Cr-Commit-Position: refs/heads/main@{#1413486}