fix return value scale of notifyANR()

fix return value scale of notifyANR()
from milliseconds to nanoseconds when windowState is not null
This prevent unintended frequent method calls of notifyANR()
in a very short time.

Change-Id: Icc1f363b3ed3538821a42c080809567473bfb833
Signed-off-by: Baik Han <baik.han@lge.com>