New SecurityFooter design

Changes:
* Footer appears below QSFooter in portrait, QSBH in landscape
* In portrait, height is 48dp for one line of text, 88dp for two lines
of text.

Creates a new layout that inherits from LinearLayout (horizontal) and
adjusts its height based on the number of lines of the containing text.

Test: manual
Test: atest QSSecurityFooterTest
Fixes: 186033456

Change-Id: Ia4f9d5c9b4078d790f654dbd4b82d14670985f8d