Commit draw state before computing whether display has content

Otherwise even if the result of WS#isDrawn is changed to true, the
state will still need to wait until next traversal to take effect.
And if there is no next traversal, the display may keep some
stale states.

Another approach is to request another traversal when the draw state
is changed, but it may add unnecessary overhead to common cases.

The reorder should be safe because the other operations which were
put before commitFinishDrawing do not check the draw state.

Bug: 307702346
Test: atest DisplayContentTests#testDisplayHasContent
Change-Id: I225fff1ff4f0738bdaf06f6813b53dbf26caf0a7