SF: fix SurfaceFlinger crash [1/1]

PD#SWPL-144146

Problem:
SurfaceFlinger crash. The race condition was described in
b/312686113#comment4.

Solution:
during VSyncDispatchTimerQueue deconstruction
skip timerCallback to avoid sf crash

Verify:
adt4, a TV set top box.

Bug: 312686113
Test: Suspend <-> resume for over 7 days. "Skip timerCallback" showed 15 times without SF crash.
Change-Id: I3cbf0294ee70dde697cba91962477d51c1bc986e
Signed-off-by: En Liu <en.liu@amlogic.com>