Allow split tile from freeform windowing in CD

This cl the bug that split tile was disabled in CD. We should only disable split select from fullscreen mode, and leave split tile from freeform windowing enabled.

Bug: 446147009
Bug: 444361656
Test: manual
Flag: com.android.window.flags.enable_non_default_display_split
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:6b3ed5a382ab0b2ec5f4f1508060e17d4975184b
Merged-In: Icacab8bef0ef460bef59e8878bbec5e0114ae99f
Change-Id: Icacab8bef0ef460bef59e8878bbec5e0114ae99f