Persist isAsciiCapable attribute of additional subtypes.

This was somehow missed in the previous commit [1] that added
isAsciiCapable attribute to InputMethodSubtype.

For devices from API level 14 to 23, IME developers might be able to
work around this issue by specifying "AsciiCapable" [2] in
imeSubtypeExtraValue, which is not coverted by CTS though.

  [1]: Ic3ace4b6e0432d56696bcbc0be336aec1dc744a5
       dc8abf6c
  [2]: I0bc9954f163a3ec38d08b9ba842a8a31176eb6a6
       8e303cc5

Bug: 27603986
Change-Id: Ifb6bc83e782ac05df180dfe0d689897d07441a0c