[ios] Rename bot configs in preparation for iOS 13.

Change-Id: I399626094a700d9b8a581591c6080da8277d584f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1611107
Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#660833}
9 files changed