Switch WindowContainer to use ConfigurationContainer

To reduce implementation dupication.
This also involved moving ConfigurationContainer to the wm package.

Test: bit FrameworksServicesTests:com.android.server.wm.ConfigurationContainerTests
Test: bit FrameworksServicesTests:com.android.server.wm.WindowContainerTests
Test: go/wm-smoke
Change-Id: Ibeca7e2ad2685f0984fccc66852d53ed9af0925f
11 files changed