Speedup the accessibility window querying APIs and clean up.

1. Now when an interrogating client requires an AccessibilibtyNodeInfo
   we aggressively prefetch all the predecessors of that node and its
   descendants. The number of fetched nodes in one call is limited to
   keep the APIs responsive. The prefetched nodes infos are cached in
   the client process. The node info cache is invalidated partially or
   completely based on the fired accessibility events. For example,
   TYPE_WINDOW_STATE_CHANGED event clears the cache while
   TYPE_VIEW_FOCUSED removed the focused node from the cache, etc.
   Note that the cache is only for the currently active window.
   The ViewRootImple also keeps track of only the ids of the node
   infos it has sent to each querying process to avoid duplicating
   work. Usually only one process will query the screen content
   but we support the general case. Also all the caches are
   automatically invalidated so not additional bookkeeping is
   required. This simple strategy leads to 10X improving the
   speed of the querying APIs.

2. The Monkey and UI test automation framework  were registering a
   raw event listener for accessibility events and hence perform
   connection and cache management in similar way to an AccessibilityService.
   This is fragile and requires the implementer to know internal framework
   stuff. Now the functionality required by the Monkey and the UI automation
   is encapsulated in a new UiTestAutomationBridge class. To enable this
   was requited some refactoring of AccessibilityService.

3. Removed the *doSomethiong*InActiveWindow methods from the
   AccessibilityInteractionClient and the AccessibilityInteractionConnection.
   The function of these methods is implemented by the not *InActiveWindow
   version while passing appropriate constants.

4. Updated the internal window Querying tests to use the new
   UiTestAutomationBridge.

5. If the ViewRootImple was not initialized the querying APIs of
   the IAccessibilityInteractionConnection implementation were
   returning immediately without calling the callback with null.
   This was causing the client side to wait until it times out. Now
   the client is notified as soon as the call fails.

6. Added a check to guarantee that Views with AccessibilityNodeProvider
   do not have children.

bug:5879530

Change-Id: I3ee43718748fec6e570992c7073c8f6f1fc269b3