Call onApplyWindowInsets after requestApplyWindowInsets

On layoutlib, requestApplyWindowInsets wasn't being passed up to
ViewRootImpl so onApplyWindowInsets wasn't being called.

Test: Added new test testApplyWindowInsets
Bug: http://b.android.com/169308
Change-Id: I8f3174dc2879a7e6c3db1628a1bfb1c023d88efc
6 files changed