IME action (done, next...) correctly handled

Bugs 5599728 and 5319237.

mInputContentType should be set for a "modern" cupcake
environment says a comment in TextView.

However, it is possible to call onEditorAction on a
TextView that didn't use any of the method that lazily
create that field. This is for instance achieved using
the extracted mode in landscape (Done, Next actions)
or in Contacts, that feature a Next/Done button in the
IME.

As a result, the action is ignored.

The patch is to force the creation of the mInputContentType
when the EditText is associated to the IME.

Change-Id: I5beec5a52e9eec0c209af37d68791bb6ff83d6f6