Passing correct displayId to modified API

1. Passing the correct displayId when calling API,
AccessibilityWindowManager#getWindowListLocked().
(The method, getWindows(), only returns the windows of default display)
2. Passing the correct displayId when calling API,
WindowManagerService#computeWindowsForAccessibility().

Bug: 134891479
Test: a11y CTS & unit tests
Test: manually test talkback AP at second display
Change-Id: I1141521d383f3c3efcf1ee32af54e12d0fcf4231