Use large label text size for action label

The large label text size is used for:
* The enter key's action label on phone/number keyboard layout of
  phone device and 7-inch tablet
* The enter key's action label on alphabet/symbols keyboard of 7-inch
  tablet.

Bug: 6509415
Change-Id: I1c0dc511b3ac87cba00163b8d29c687ad1e86ce8