Merge pull request #14508 from julienw/942863-use-height-instead-of-border-bottom

Bug 942863 - Workaround for a Gecko bug in SMS app with APZ enabled. r=borja
(cherry picked from commit b44a75862ebcb651381eabc9c3a3b203d76d63bf)
Merge pull request #14614 from Rik/call-screen-banner-multiline-946742

Bug 946742 - Message overlapped during multiparty when a call is released r=etienne
(cherry picked from commit 0ee9b91a5cf770c099ecaeaadf85fec9c493f53d)