Modifying the mechanism of A11y window cache

For supoorting new API as below, the A11y window cache needs to modify
from one dimension to two dimension. The first dimension is window Id,
the second(new) dimention is the display Id.
SparseArray<List<AccessibilityWindowInfo>> getWindowsOnAllDisplays()

Bug: 133279356
Test: a11y CTS & unit tests
Change-Id: Ida49ef22de67bd81353a896491dcae56ed751fd1
3 files changed