Skip AE tests for devices without multi-window support

AE is not meant to support on some devices
even if Window Extensions library issupported in some cases.
An example is Android TV devices with GSI, which supports
Window Extensions library by default, but doesn't support
showing multiple activities for most products.

Test: atest cts/tests/framework/base/windowmanager/jetpack/src/android/server/wm/jetpack/embedding
Fixes: 293839942
Fixes: 295784230
Change-Id: Id05cabcb3b678e4be315a1b3aa0c78bbd8478b9e