Fix for IOOB in SearchView

Bug 6476578

The latest bug report show a query.length() of 33 while
mQueryTextView.length() is 0 on line 514.

I can see 2 reasons which can explain this discrepancy:
- the mQueryTextView has a filter, which alters the text.
- some asynchronous event (IME?) changes the text in the mean time.

I would favor the second one, which seems to break a lot of single
thread assumptions in the code and generates other IOOB exceptions.

Note that depending on what they are used for, it may be more consistent
to use mQueryTextView.getText() instead of query in the following
assignment.

Change-Id: Ie8a5486b11a80543f8f90980454933c5a74c073e