Merged requested to merge roman.stratiienko/drm-hwcomposer:rework-flattening into main
Depends on !222 (merged) !221 (merged)
Using vsync means consume some CPU time every frame for IRQ -> Kernel_Thread -> UserSpace_listener thread transitions.
Framework tries to reduce vsync usage to the minimum, by using timelines instead.
New flattening controller thread wakes-up only once per second.
This commit also removes flattening info from dumpsys. Practice shows that it is almost useless. Instead debugging can be done using ALOGV dumps.