Add highlight API for search result range

The search result highlight API is added next to the highlight APIs
becasue of following reasons.
- The search result API draws always top of the developer given
  highlight APIs.
- highlight and focused highlight color should be customizable by
  themeing.

Bug: 244502332
Test: atest android.widget.cts.TextViewSearchResultHighlightTest
Change-Id: Idb52e7080ee33a5315878e42a3d7349bc3a90627