Use the new web email and password variations.

Bug:2460543
Bug:3094312
Bug:2692655
Bug:2710595

Use the NEXT flag when there is a following
textfield.

In TextView, treat the new variations like email and password
variations.

Requires a change in LatinIME so that these fields work propely:
https://android-git.corp.google.com/g/#change,77721

Change-Id: Id6517a016db7d50b77570ff77f2635027796da4a