More 1.19 backwards compatibility fixes

Fixed dependencies for 1.19 and made sure POST HTTP method
is uppercase since it has to be in 1.19.

Also removed {{SITENAME}} magic from JavaScript messages,
since it is way more difficult making that work in 1.19.

Bug: 55975
Change-Id: Ia8c0004242cd1ed69b69b626de6ed4d8e23790a9
Merge "More 1.19 backwards compatibility fixes"