Revert of [ObjC ARC] Converts ios/chrome/browser/ui/stack_view:stack_view to ARC. (patchset #3 id:40001 of https://codereview.chromium.org/2810193004/ )

Reason for revert:
Causes crashes of ios_chrome_integration_egtests, ios_chrome_settings_egtests, and ios_chrome_ui_egtests test suites. Ref: https://build.chromium.org/p/chromium.fyi/builders/EarlGreyiOS/builds/27109

Original issue's description:
> [ObjC ARC] Converts ios/chrome/browser/ui/stack_view:stack_view to ARC.
>
> Automatically generated ARCMigrate commit
> Notable issues:None
> BUG=624363
> TEST=None
>
> Review-Url: https://codereview.chromium.org/2810193004
> Cr-Commit-Position: refs/heads/master@{#468634}
> Committed: https://chromium.googlesource.com/chromium/src/+/ba4d7df1bcc063577dc66378f7465120fce5468a

TBR=marq@chromium.org,stkhapugin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=624363

Review-Url: https://codereview.chromium.org/2859503002
Cr-Commit-Position: refs/heads/master@{#468664}
16 files changed