Avoid hard-coded value in test setup and teardown.
Merge pull request #15712 from zuhao/refactor_actionview_javascript_helper_test

Avoid hard-coded value in test setup and teardown.
Use `@existing_user` while updating existing user, fixing - #ee4e86
pg guide, use the term `database views` to be specific. [ci skip]
Merge pull request #15717 from akshay-vishnoi/test-cases

Use `@existing_user` while updating existing user, fixing - ee4e86