Add dispatchRequestTranslation() in WebViewProvider.

This change doesn't introduce a new API, the change is just pushing
down an existing API from View that we are missing to add for the
webview. We should also provide this method to allow webview provider
to provide their implementation if needed.

Bug: 186617107
Test: manual
CTS-Coverage-Bug: 177960696

Change-Id: If75285b3aafdb1f2a3d7c307a90bb783edf029b5