Update posturing detection to reduce false positives

Implements a sliding window algorithm for motion and orientation. We use
a 10 second window, but this is tunable.

Bug: 396460215
Test: atest PosturingInteractorTest
Flag: android.service.dreams.allow_dream_when_postured
Change-Id: Id6eddba52fb0927e561f79e5acf579a353c0cd3e