leanback: workaround RV focusSearch() issue.

CL "RecyclerView focus search improvements" breaks the scenario
to keep focus within RV when regular FocusFinder fails.

Returning same focused view in onFocusSearchFailed() is no longer
working since RV.isPreferredNextFocus() rejects it.

This workaround moved logic from onFocusSearchFailed to
onInterceptFocusSearch.

Bug 28246268
Bug 28256038
Bug 28270709

Change-Id: Iabe4b981c40f0282ef0d8d370669692ca612d727
1 file changed