Moving cursor to the end of the search query when set explicitly.

This situation is encountered in Contacts when the activity
intercepts unsolicited input from the keyboard, takes that
character entered by the user and switches the whole app
to "search mode".  At this time it puts the character
entered by the user in the search field. The user should be
able to continue typing.

Change-Id: Ief40f12bb8f31bced6114d61a0fd95472f21b1be