Added IWindowInfosChangedListener interface

Added WindowInfosChangedListener interface and the ability to
register a WindowInfosChangedListener in SCC. Also added the
SurfaceFlinger code where the WindowInfosChangedListener gets
registered and reports to the listeners.

Test: Existing tests pass
Bug: 188792659
Change-Id: If7b93df0afd71a88ea703d2113e68bfb549368af
16 files changed