Make veaction=edit work regardless of user preference

Move the userPrefEnabled check out of isAvailable and instead check
it in-line with isAvailable for setting up the tabs with CSS, but
not for the veaction=edit function.

Bug: 55900
Change-Id: I23984e377ff3fc797e921546492b8c73a5101235
Merge "Make veaction=edit work regardless of user preference"