Fix for the missing focus in WebView form fields.

This looks like a regression for WebView (58.0.3029.125) in android
'O'. But this seems to have been fixed in early version of 60 (webview).
This workaround gets us past the problem, until we get the newer version
of WebView.

Bug: 62449959
Test: Manual
Change-Id: I29883bf7d1567c1ce7be90b4efde4b3da93b99a2
(cherry picked from commit 97640400)