Ignore orientation request in ActivityEmbedding split

We used to ignore orientation request when the activity is in
multi-window, but the behavior is changed in cl[1].

However, it breaks the existing usages, so keep it ignoring until we can
better handle this for ActivityEmbedding.

[1]: I2d9a89959f7203963830fc12063bda76e0c73c1e

Fix: 232484177
Test: atest WmTests:TaskFragmentTest
Change-Id: Ia01edcf755583e8e6a83d95fc1cad52ec0bf997e