Choose TDA by DisplayAreaPolicy for WindowContext

Previously, WMS always associate TYPE_APPLICATION WindowContext with
the default TDA. This CL provides the capibility to select a TDA by
DisplayAreaPolicy.

Test: atest DisplayAreaPolicyBuilderTest
fixes: 185769955

Change-Id: Ie7cb686cd5d1da81ef618a3f1316dc3932a8272f
5 files changed