Add support for parsing states.

Add support for parsing half-opened and flat states.
Update SampleSidecar to fallback to display feature state if missing.
Add the ability to normalize display feature states.

Bug: 183049815
Test: Manual
Test: Make sure either sidecar or extensions is installed.
Test: adb shell settings put global display_features fold-[0,960,1080,960]-flat
Test: Run sample app from window-samples in jetpack
Test: Verify there is a feature.
Test: Note the dimensions are device dependent.
Change-Id: Iadbca299b37ca1ed6c62adfc83fd091dbe911d0c