Set brave wallet string state synchronously.

[aseren]

When wallet is first created, it is written to profile prefs by asynchronous SetStringState mojo call (in Wallet::SetWallet function). After that wallet is requested shortly by running synchronous GetStringState mojo call (in PostWalletBrave::Request function). This leads to race condition so requested wallet could be null (it happens due to mojo async tasks queue execution is interrupted on mojo sync tasks execution).

This PR changes wallet set state mojo calls to synchronous calls (like SetStringState)

Resolves brave/brave-browser#21809

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally: npm run test -- brave_browser_tests, npm run test -- brave_unit_tests, npm run lint, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

• Need to confirm that we able to create a wallet on clean install.
• Trigger an ad, confirm we got credited for viewing it
• Confirm tips are processed

[zenparsing]

It seems to me that all of the Set*State methods are going to be prone to the same race condition.

As far as I know, all the "Set" methods are used exactly as if they were sync. Instead of introducing a "Sync" version of SetStringState, can we just add the [Sync] attribute to all of these "SetState" methods?

[aseren]

Done, thanks for the idea!

[emerick]

LGTM

[kjozwiak]

Verification PASSED on Win 11 x64 using the following build(s):

Brave | 1.39.28 Chromium: 100.0.4896.60 (Official Build) nightly (64-bit)
-- | --
Revision | 6a5d10861ce8de5fce22564658033b43cb7de047-refs/branch-heads/4896@{#875}
OS | Windows 11 Version 21H2 (Build 22000.593)

• ensured that creating a Brave Wallet via brave://wallet worked without any issues on new profiles
• ensured that users can trigger ad notifications and are being credited

[17832:8708:0405/024937.703:VERBOSE1:ad_notification_serving.cc(142)] Found 1 eligible ads
[17832:8708:0405/024937.703:VERBOSE1:ad_notification_serving.cc(266)] Serving ad notification:
  uuid: b15ae4fa-79ad-406f-b67d-618223dad35e
  creativeInstanceId: f9a0eac9-a311-4189-ba46-e96dbbfc3f05
  creativeSetId: c2ec9fda-9fff-437c-97d5-b211315ef0c4
  campaignId: c67c92ca-6eba-4d49-85cb-3cabfe608dab
  advertiserId: 247767b8-0eef-4349-83fd-a51d0f4d9a55
  segment: business
  title: Sophos Incident Response Guide
  body: Discover the 10 steps you need to take to stop a cyberattack
  targetUrl: https://secure2.sophos.com/en-us/security-news-trends/whitepapers/gated-wp/incident-response-guide.aspx?cmp=120536&utm_source=brave&utm_medium=cpc&utm_campaign=GPD-2021-NA-Display-Brave-Push-Notification-Incident-Response-Guide-DG-120536&utm_content=push-note

[17832:8708:0405/024939.614:VERBOSE1:confirmations.cc(60)] Confirming click for ad_notification with transaction id 26e4acff-ea34-4695-b9ad-dec5e989207d and creative instance id f9a0eac9-a311-4189-ba46-e96dbbfc3f05

• ensured that tips are being processed

[47444:44176:0405/025436.895:VERBOSE1:contribution.cc(388)] Creating contribution for wallet type uphold (amount: 1, type: ONE_TIME_TIP)
[47444:44176:0405/025436.901:VERBOSE1:contribution.cc(117)] Queue timer set for 4 s
[47444:44176:0405/025436.902:VERBOSE1:database_server_publisher_banner.cc(142)] Server publisher banner not found
[47444:44176:0405/025436.902:VERBOSE5:ledger_impl.cc(119)]
[ REQUEST ]
> URL: https://api.uphold.com/v0/me/cards/a571b03e-b504-4ee8-adc5-bf93e5dca8ab/transactions
> Method: POST
> Content: {"denomination":{"amount":"0.950000","currency":"BAT"},"destination":"7b23cde4-226b-4cd1-87af-fc4ab5c4f1f2","message":""}
> Content Type: application/json; charset=utf-8
[47444:44176:0405/025437.043:VERBOSE6:logging_util.cc(137)]
[ RESPONSE - OnRequest ]
> Url: https://api.uphold.com/v0/me/cards/a571b03e-b504-4ee8-adc5-bf93e5dca8ab/transactions
> Result: Success
> HTTP Code: 202