1. The function for finding where the accessibility focus in a virtual
node tree presented by an AccessibilityNodeProvider is not needed
API since the framework already keeps track of the accessibility
focused virtual node in order to draw the focus rectangle. This API
adds unnecessary complexity to developers of AccessibilityNodeProviders.
bug:6675330
Change-Id: I84774686b06a995073a39e45b8ef22f2cd04b773