Drawing app theme snapshot without hold wm lock.

A potential deadlock could happen when hold wm lock and require
hardware buffer from createHardwareBitmap, the rendering thread can be
blocked because it is waiting for dequeue buffer.
Defer the create snapshot process in a supplier, to escape the wm lock
if the snapshot should be draw by render thread.
Also add a parameter allowAppTheme in captureSnapshot, then the caller
can decide to not capture fake snapshot.

Flag: com.android.window.flags.exclude_drawing_app_theme_snapshot_from_lock
Bug: 373502791
Test: atest ActivitySnapshotControllerTests TransitionTests
TaskSnapshotControllerTest
Test: verify there won't block render thread while capture app snapshot
for app theme mode.

Change-Id: I7add8baecb0d068bac485fe9eee0c90f23d2f823