[OOBE]: Make sure booting animation is shown first

Bug: b:269104368
Change-Id: I597b3f26919790d37e97b2f2b6dacd5e8ed3eeb2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4549487


Commit-Queue: Danila Kuzmin <dkuzmin@google.com>
Reviewed-by: Renato Silva <rrsilva@google.com>
Cr-Commit-Position: refs/heads/main@{#1147419}