Correct the deferred sending of display events.

When multiple processes sharing the same uid become non-cached, the
current deferred transmission logic does not consider all of them,
leading to only the first process in the callback list to receive the
pending display events. Moreover, this first process may inadvertently
receive unintended display events.

Bug: 325692442
Test: manual, see bug description

Change-Id: Ife98a8d843a3000294fbc9929bb78a755534b5dc
Signed-off-by: Hyeongseop Shim <hyeongseop.shim@samsung.corp-partner.google.com>