Fix NPE when record histoy

It seems occured while search view is still not injected, so we can
prevent this by return when no any search string.
Check search view null or not to ensure do not cause any NPE.

Fix: 140251324
Test: atest DocumentUIGoogleTests
Change-Id: Ib62e8a25e66302a785f638a463049d36f9e25a36