[iOS] Updating iOS signout policies to use the profile switch util

The IdleTimeoutAction "sign_out" currently signs out of the current
account, which will not be possible with multiple profiles. This CL
changes the behaviour to switching profile for the sign out action when
multiple profiles are enabled. Note than in the case of becoming idle
while multiple profiles are open, the dialog only shows in one window
similar to the desktop implementation:
https://docs.google.com/presentation/d/104WurBb0lCS-bfhYXZ_2WSXO21t-er9qEHIgic5hqJc/edit?resourcekey=0-vKMOxctNdbPKLwOWme0GZQ#slide=id.g22f5b3bb56c_0_18

BrowserSignin disabled policy is also updated to use the same helper.

Screen recordings: https://drive.google.com/corp/drive/folders/1BfPTdcioeuZ2_mg4lz5UU3ytwKjUPYFQ?ths=true

Bug: 364574533
Change-Id: I0cf64be29c83352e3a816ca2ea66057ea0279dcd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6180164
Commit-Queue: Salma Elmahallawy <esalma@google.com>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1416210}
NOKEYCHECK=True
GitOrigin-RevId: 86716e69855190baa56599e82f62c8eee63350ac
12 files changed
tree: 5fa5394e06b1760a1b688cc28f3342cdea7834d0
  1. build/
  2. chrome/
  3. components/
  4. google_internal/
  5. intents/
  6. net/
  7. public/
  8. testing/
  9. third_party/
  10. tools/
  11. web/
  12. web_view/
  13. .swift-format
  14. BUILD.gn
  15. COMMON_METADATA
  16. DEPS
  17. DIR_METADATA
  18. features.gni
  19. OWNERS
  20. PRESUBMIT.py
  21. PRESUBMIT_test.py
  22. README.md
README.md

This directory holds code related to Chrome for iOS. See this document for a description of the structure underneath this directory.