Don't submit a query if it's whitespace only.

Just to maintain backward compatibility. It's not documented that a space
is not a valid query, but it does make sense to expect that.
Bug: 5079755

Also avoid showing an x by an empty query, by having the SearchDialog simulate an ActionBar.

Change-Id: I3a9332286a439b659e179a249587c491ef29e5c1
2 files changed