Check Task windowing mode when reporting display features

If an application uses ActivityEmbedding it would not be able to
observe display features (like folds or hinges) because they are
filtered out for activities in multi-window mode. One of the reasons
is because the client won't always know the correct position of the
window on screen in multi-window, and the position of the hinge could
be translated incorrectly to the task coordinate space.

However, it would still be OK to report the display features
when activities are in multi-window due to ActivityEmbedding as
long as the task is not in multi-window.

Bug: 236295340
Test: Sample app with embedding and display features.
Change-Id: I00f62574124df6df61f121228bd91ff9bc751c2a