Add bsazonov to components/account_manager_core/OWNERS

Bug: None
Change-Id: I64f193a4b0ba424e3989ccedfb66e921478483f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2611099Reviewed-by: Kush Sinha <sinhak@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842027}

components/account_manager_core/OWNERS

 file://chromeos/components/account_manager/OWNERS
+bsazonov@chromium.org