Don't restart input in the middle of a batch.

 Bug 6854156
 setComposingText is in the middle of a batch and it was resetting
 the InputConnection. When the batch ended, it was closing a
 batch that wasn't open on the new InputConnection. The reset
 turns out not to be necessary anymore -- the LatinIME respects
 the content when setComposingText fails to change anything.

Change-Id: If3352b32ed7b3c90c8dcb3d5ff8d308e82849d85