Prevent AccessibilityInteractionClient.getWindows()

returns partially cached windows list.

It could happen that AccessibilityWindowInfo cache is
cleared. And after that calling
AccessibilityInteractionClient.getWindow(windowId)
would add that window to cache. And while cache is
not empty after that AccessibilityInteractionClient
returns its content on getWindows() request even
if it does not contain all windows.

Change-Id: I70dc96d50e3368285fd482a98769a93ae2c15f22