Add missing auto-fill strings.

These strings had a defintion native side, but no corresponding
definition java side which would lead to a crash. Strings taken from
chrome/app/generated_resources.grd - see
http://src.chromium.org/viewvc/chrome/trunk/src/chrome/app/generated_resources.grd?r1=75912&r2=76117&pathrev=88489

Also note that credit_card_number_preview_format is no longer needed.

See also change Ib861245e26197938bb2c5cf0f99c1d797ab0fbf2

Change-Id: I829b5d24e6f9a04211ee91c3f670c8659c004cd9