base: App crash when select suggestion's length more than specified.

App crashed by catch IndexOutOfBoundsException which raised
by check span range when select suggested string.The root
cause is that the editor will truncate the suggested string
which length is more than it specified, but it also set span
use the suggestion's original length.

Update the suggestion's real length after editor replace the
original string to suggested.

Change-Id: I2d765701934a9e68be172cb87a104590f3cdeceb
CRs-Fixed: 532211