Hygiene: Cleanup browser test steps which are not sentence case

When tied to a keyword Given, When or Then if not in sentence
case the steps are not grammatically correct.

Let's avoid broken windows and bad cargo cult programming by standardising
on this.

See: https://m.mediawiki.org/wiki/MobileFrontend/Coding_conventions#Browser_tests

Change-Id: I95d8cef3965d4c742fca4eae9c2eb37c13406a37
Merge "Hygiene: Cleanup browser test steps which are not sentence case"