DirectReply: Prevent closing the IME window on reinflation

Fixes a bug where the IME window would close if
the notification gets reinflated while direct reply
is open.

Change-Id: I37b8b29abe6b36c24e9a8bbf86f346523f1a4203
Fixes: 31181080
Test: manually; receive hangouts message, open direct reply, receive
      second message. Observe if IME closes.