Add ANIM_FROM_STYLE to the list of animations that the default Shell transition handler can run.

WindowAnimationStyle theme attribute in Shell support was added in ag/16431811 but isSupportedOverrideAnimation was never updated to indicate that ANIM_FROM_STYLE can be supported.

Change-Id: I10e348ccce5deca86ed9197347942a332b8c307d
Test: Make sure demo app with ActivityEmbedding with custom animations set using WindowAnimationStyle actually uses the custom animation. (ActivityEmbeddingController is the only callsite for isSupportedOverrideAnimation.)
Flag: EXEMPT bugfix
Bug: 206960607
Bug: 293658614