Uplift don't ask again in private window fix to 0.71.x

[yrliou]

Uplift of #3673

[yrliou]

Only test failures are lint and seems impossible to be related to this PR.

01:17:52  + git -C src/brave config user.name jenkins
01:17:52  + git -C src/brave config user.email no@reply.com
01:17:52  + git -C src/brave checkout -b TEMP_LINT_BRANCH_1
01:17:52  Switched to a new branch 'TEMP_LINT_BRANCH_1'
01:17:52  M	package-lock.json
01:17:52  + npm run lint -- --base=origin/0.71.x
01:17:52  
01:17:52  > brave@0.71.90 lint /Users/jenkins/jenkins/workspace/ix_private_dont_ask_again_0.71.x
01:17:52  > node ./scripts/commands.js lint "--base=origin/0.71.x"
01:17:52  
01:17:52  /Users/jenkins/jenkins/workspace/ix_private_dont_ask_again_0.71.x/src/brave: python /Users/jenkins/jenkins/workspace/ix_private_dont_ask_again_0.71.x/scripts/lint.py --project_root=/Users/jenkins/jenkins/workspace/ix_private_dont_ask_again_0.71.x/src --base_branch=origin/0.71.x
01:17:53  Traceback (most recent call last):
01:17:53    File "/Users/jenkins/jenkins/workspace/ix_private_dont_ask_again_0.71.x/scripts/lint.py", line 20, in <module>
01:17:53      import git_cl
01:17:53    File "/Users/jenkins/jenkins/workspace/ix_private_dont_ask_again_0.71.x/vendor/depot_tools/git_cl.py", line 40, in <module>
01:17:53      import auth
01:17:53    File "/Users/jenkins/jenkins/workspace/ix_private_dont_ask_again_0.71.x/vendor/depot_tools/auth.py", line 12, in <module>
01:17:53      import httplib2
01:17:53  ImportError: No module named httplib2
01:17:53  null
01:17:53  null
01:17:53  npm ERR! code ELIFECYCLE
01:17:53  npm ERR! errno 1
01:17:53  npm ERR! brave@0.71.90 lint: `node ./scripts/commands.js lint "--base=origin/0.71.x"`
01:17:53  npm ERR! Exit status 1
01:17:53  npm ERR! 
01:17:53  npm ERR! Failed at the brave@0.71.90 lint script.
01:17:53  npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
01:17:53  
01:17:53  npm ERR! A complete log of this run can be found in:
01:17:53  npm ERR!     /Users/jenkins/.npm/_logs/2019-10-11T08_17_52_824Z-debug.log

[bsclifton]

Changes already merged to master and 0.69.x! Verified CI looks great 😄 Thanks!