We want to merge all the branding work into the MobileFrontend master branch but we want to feature flag switching from a search input to a search icon. The following steps need to occur:
 Ensure T157987 has been merged
 Merge contents of branding branch onto master
 Create a new task when the switchover has been merged as a reminder to remove css for cached HTML
* We should merge via a squash to allow us to revert easily if possible (we can leave all the change ids of the individual commits in the commit message)
* No need to SWAT - just let it ride the train.