Rename "big" to "contentView"

In methods like applyStandardTemplateWithActions, this name is confusing
because the method isn't used strictly for expanded views (it's also
used for HUNs for example). We're also trying to move away from the name
"big" anyway, so let's make things consistent.

Flag: EXEMPT simple rename
Test: builds
Change-Id: I34877f34f659db955d27483692257105b138c6b5