On first boot for Japan region, have a tab pre-opened to a specific webpage

[Miyayes]

Description

When a user boots up the browser for the first time in Japan, another background tab (not focused, and not interacting with the brave://welcome experience) can already be opened to a certain webpage/URL.

[LaurenWags]

Verified passed with

Brave	1.25.64 Chromium: 90.0.4430.212 (Official Build) beta （x86_64）
変更履歴	e3cd97fc771b893b7fd1879196d1215b622c2bed-refs/branch-heads/4430@{#1429}
OS	macOS バージョン10.15.7（ビルド19H1030）

Verified scenarios listed in brave/brave-core#8686 (comment)

Scenario 1 - clean profile Japan region

Verified test plan from brave/brave-core#8686.
Confirmed brave://welcome was opened and active tab.
Confirmed https://brave.com/ja/users-bitflyer/ was opened in background tab.
Confirmed if brave://welcome and the blog page are closed and a new tab is opened, when browser is relaunched another background tab with the blog is not opened.
Confirmed if brave://welcome is closed and the blog page is opened, when the browser is relaunched another background tab with the blog is not opened.

Additional testing done with #15794.

Scenario 2 - clean profile non-Japan region

Used US for non-Japan region.

Confirmed on clean install no secondary (background) tab was opened with blog.
Closed and relaunched several times, confirmed no additional tab was opened.

Scenario 3 - upgrade profile Japan region

Installed 1.24.85 and visited a few sites.
Closed 1.24.85.
Renamed profile to Brave-Browser-Beta.
Launched with 1.25.x.
Confirmed no background tab w/ the blog was opened.
Closed/reopened several times.
Confirmed no background tab w/ the blog was opened.

Scenario 4 - upgrade profile non-Japan region

Used US for non-Japan region.

Installed 1.24.85 and visited a few sites.
Closed 1.24.85.
Renamed profile to Brave-Browser-Beta.
Launched with 1.25.x.
Confirmed no background tab w/ the blog was opened.
Closed/reopened several times.
Confirmed no background tab w/ the blog was opened.

---

Verification passed on

Brave | 1.25.64 Chromium: 90.0.4430.212 (Official Build) beta (64-bit)
-- | --
Revision | e3cd97fc771b893b7fd1879196d1215b622c2bed-refs/branch-heads/4430@{#1429}
OS | Windows 10 OS Version 2004 (Build 19041.985)

Verified scenarios listed in brave/brave-core#8686 (comment)

Scenario 1 - clean profile Japan region

Verified test plan from brave/brave-core#8686.
Confirmed brave://welcome was opened and active tab.
Confirmed https://brave.com/ja/users-bitflyer/ was opened in background tab.
Confirmed if brave://welcome and the blog page are closed and a new tab is opened, when browser is relaunched another background tab with the blog is not opened.
Confirmed if brave://welcome is closed and the blog page is opened, when the browser is relaunched another background tab with the blog is not opened.

Additional testing done with #15794.

Scenario 2 - clean profile non-Japan region

Used US for non-Japan region.

Confirmed on clean install no secondary (background) tab was opened with blog.
Closed and relaunched several times, confirmed no additional tab was opened.

Scenario 3 - upgrade profile Japan region

Installed 1.24.85 and visited a few sites.
Closed 1.24.85.
Renamed profile to Brave-Browser-Beta.
Launched with 1.25.x.
Confirmed no background tab w/ the blog was opened.
Closed/reopened several times.
Confirmed no background tab w/ the blog was opened.

Scenario 4 - upgrade profile non-Japan region

Used US for non-Japan region.

Installed 1.24.85 and visited a few sites.
Closed 1.24.85.
Renamed profile to Brave-Browser-Beta.
Launched with 1.25.x.
Confirmed no background tab w/ the blog was opened.
Closed/reopened several times.
Confirmed no background tab w/ the blog was opened.

---

Verification passed on

Brave	1.25.65 Chromium: 91.0.4472.57 (Official Build) (64-bit)
Revision	e3443317fa07f1e9997e4a9c738eddfefc3c0292-refs/branch-heads/4472_54@{#6}
OS	Ubuntu 18.04 LTS

Verified scenarios listed in brave/brave-core#8686 (comment)

Scenario 1 - clean profile Japan region

Verified test plan from brave/brave-core#8686.
Confirmed brave://welcome was opened and active tab.
Confirmed https://brave.com/ja/users-bitflyer/ was opened in background tab.
Confirmed if brave://welcome and the blog page are closed and a new tab is opened, when browser is relaunched another background tab with the blog is not opened.
Confirmed if brave://welcome is closed and the blog page is opened, when the browser is relaunched another background tab with the blog is not opened.

Additional testing done with #15794.

Scenario 2 - clean profile non-Japan region

Used US for non-Japan region.

Confirmed on clean install no secondary (background) tab was opened with blog.
Closed and relaunched several times, confirmed no additional tab was opened.

Scenario 3 - upgrade profile Japan region

Installed 1.24.85 and visited a few sites.
Closed 1.24.85.
Launched with 1.25.x.
Confirmed no background tab w/ the blog was opened.
Closed/reopened several times.
Confirmed no background tab w/ the blog was opened.

Scenario 4 - upgrade profile non-Japan region

Used US for non-Japan region.

Installed 1.24.85 and visited a few sites.
Closed 1.24.85.
Launched with 1.25.x.
Confirmed no background tab w/ the blog was opened.
Closed/reopened several times.
Confirmed no background tab w/ the blog was opened.