ANDROID: Revert "io_uring: rely solely on FMODE_NOWAIT"

This reverts commit caec5ebe.

This commit is the reason for two (related?) issues on Pixel6:
* TH can't flash devices in fastbootd
* not all drivers are being bound to devices

Revert while we further investigate the issue.

Test: manual boot test, TH
Bug: 290862678
Change-Id: I35eeb77ab1545a4176ca4660e576ace1b23968f3
Signed-off-by: André Draszik <draszik@google.com>