Fixed no alert text shown when there is alert

Fixed by hiding the text when there is alert, and
then unhide it when there is no alerts at beginning
or after history cleared.

Test: Manual
Bug: 131642555
Merged-In: Ieca1bc28a6aee52a699ee408888087e30edf1d54
Change-Id: Ieca1bc28a6aee52a699ee408888087e30edf1d54
(cherry picked from commit 468b75b68ca0642cd3c4203760790f99072b373a)
1 file changed