Android lollipop shared elements transition blink / flash
Hurray! I've managed to solve this problem.
Blinking screen is common problem described here: Blinking screen on image transition between activities (thx @AlexLockwood)
Blinking shared element was caused by DrawerLayout. I was starting new Activity to soon. When I've moved ActivityCompat.startActivity to DrawerLayout.DrawerListener's onDrawerClosed method everything started working like a charm.