The search box in header disappear at the breakpoint of 769px

[KelvinWong]

Steps to re-produce

1. Go the example page form the health design system:
   https://designsystem.health.gov.au/components/preview/search-page.html
2. View the page with a screen width of 769px

Results:
The search box is not exist in the header, and there is no way to do searching.

Investigation

• The mobile search box shows up when screen size is less than or equal to 767px.
• The desktop search box kicks in when screen size is greater than equal to 770px.
• When the screen size is 768px and 769px in width, no search box is available.
• 768px width is a screen size of the iPad in portrait mode.

[KelvinWong]

I have provided a path to fix that.

iss52_fix_missing_search_box_in_certain_breakpoints.patch.gz