[Sync] Warn if OS Keychain is locked or impossible to decrypt sync code words

[AlexeyBarabash]

If OS Keychain is locked and/or impossible to decrypt sync code words, then sync doesn't work.
Also there is a crash when trying to display QR code.

Steps to reproduce:

1. Setup sync chain
2. Exit browser
3. Lock the keychain
4. Launch browser and deny keychain access
5. Show sync code words.
   Actual - there is one word.
   Expected not to have any words.
6. Show QR code
   Actual - crash happens
   Expected not to crash at least.

Required:

• display no words in such case;
• do not have a crash;
• provide additional info about Keychain state and code words decryption result in sync-internals.

Reproduced on Ubuntu and macOS.

[kjozwiak]

The above will require 1.43.83 or higher for 1.43.x verification 👍

[stephendonner]

Verification PASSED using

Brave	1.43.84 Chromium: 105.0.5195.68 (Official Build) (x86_64)
Revision	ad13e82529051bac6a0e65f455e6d7a1e5fd7938-refs/branch-heads/5195@{#903}
OS	macOS Version 11.6.8 (Build 20G730)

Followed Kamil's modified testplan: brave/brave-core#14224 (comment)

Steps:

1. installed 1.43.84
2. launched Brave
3. loaded brave://sync-internals
4. ensured Passphrase is set was set to false
5. ensured OS encryption available was set to true
6. loaded brave://sync/
7. clicked on Start using sync
8. clicked on Start a new Sync Chain
9. click on Computer
10. click OK
11. loaded brave://sync-internals/
12. confirmed Passphrase is set is true
13. confirmed OS encryption available is true
14. shut down Brave
15. removed Brave Browser access to the Brave Safe Storage using Keychain Access
16. launched Brave
17. loaded brave://sync-internals
18. ensured Passphrase is set is true
19. ensured Passphrase decryption failed is true
20. ensured OS encryption available is false
21. confirmed I got the Sync service could not be started, Sync is not running notification
22. confirmed clicking on Check details takes me to brave://settings/braveSync/setup
23. confirmed clicking on the troubleshooting link loads https://support.brave.com/hc/en-us/articles/360047642371-Sync-FAQ correctly
24. ensured that the Sync service could not be started, Sync is not running notification re-appears when re-launching the browser after dismissing the notification via X
25. ensured that the Sync service could not be started, Sync is not running notification re-appears when re-launching the browser after dismissing the notification by clicking on Check details
26. ensured that the Sync service could not be started, Sync is not running notification doesn't re-appear when re-launching the browser after the user has dismissed the notification via Don't show again.
27. shut down Brave
28. granted Brave Browser access to the Brave Safe Storage via Keychain Access
29. launched Brave
30. clicked on Deny on the Brave Safe Storage dialog
31. load brave://sync-internals
32. confirmed Passphrase is set -> true
33. confirmed Passphrase decryption failed -> true
34. confirmed OS encryption available -> false
35. shut down Brave
36. launched Brave
37. entered my password for Keychain Access and clicked on Always Allow on the dialog
38. added my iPhone via brave://sync/ and confirmed it's working
39. loaded brave://sync-internals
40. noted Passphrase is set is true and OS encryption available is true

steps 4-5	steps 12-13	step 15	steps 17-20	steps 21-22	step 23	step 28	step 30	steps 31-34	step 38	steps 39-40

---

Verification passed on

Brave	1.43.85 Chromium: 105.0.5195.68 (Official Build) (64-bit)
Revision	ad13e82529051bac6a0e65f455e6d7a1e5fd7938-refs/branch-heads/5195@{#903}
OS	Ubuntu 18.04 LTS

Followed Kamil's modified testplan: brave/brave-core#14224 (comment)

Steps:

1. installed 1.43.85
2. launched Brave
3. loaded brave://sync-internals
4. ensured Passphrase is set was set to false
5. ensured OS encryption available was set to true
6. loaded brave://sync/
7. clicked on Start using sync
8. clicked on Start a new Sync Chain
9. click on Computer
10. click OK
11. loaded brave://sync-internals/
12. confirmed Passphrase is set is true
13. confirmed OS encryption available is true
14. shut down Brave
15. removed Brave Browser access to the Brave Safe Storage using Keychain Access
16. launched Brave
17. loaded brave://sync-internals
18. ensured Passphrase is set is true
19. ensured Passphrase decryption failed is true
20. ensured OS encryption available is false
21. confirmed I got the Sync service could not be started, Sync is not running notification
22. confirmed clicking on Check details takes me to brave://settings/braveSync/setup
23. confirmed clicking on the troubleshooting link loads https://support.brave.com/hc/en-us/articles/360047642371-Sync-FAQ correctly
24. ensured that the Sync service could not be started, Sync is not running notification re-appears when re-launching the browser after dismissing the notification via X
25. ensured that the Sync service could not be started, Sync is not running notification re-appears when re-launching the browser after dismissing the notification by clicking on Check details
26. ensured that the Sync service could not be started, Sync is not running notification doesn't re-appear when re-launching the browser after the user has dismissed the notification via Don't show again.
27. shut down Brave
28. granted Brave Browser access to the Brave Safe Storage via Keychain Access
29. launched Brave
30. clicked on Deny on the Brave Safe Storage dialog
31. load brave://sync-internals
32. confirmed Passphrase is set -> true
33. confirmed Passphrase decryption failed -> true
34. confirmed OS encryption available -> false
35. shut down Brave
36. launched Brave
37. entered my password for Keychain Access and clicked on Always Allow on the dialog
38. added another device via brave://sync/ and confirmed it's working
39. loaded brave://sync-internals
40. noted Passphrase is set is true and OS encryption available is true

steps 4-5	steps 12-13	step 15	steps 17-20	steps 21-22	step 23	step 30	steps 31-34	step 38	steps 39-40