All SuggestionSpans are removed when the window loses focus.

SuggestionSpans should have a limited, well defined life-span.
Saving these in onSaveInstanceState is inappropriate since these can
be very large and will not necessarily be saved/loaded by the application.

Keeping them in the application when it is dismissed is not consistent
since they may be garbage collected while the application is not active.

Change-Id: Icebf6cb0218528f9d162a689ad33efeb770fbede