Ensure parsing PROPERTY_FEATURE_REAR_DISPLAY_OUTER_DEFAULT

Update DeviceStateProviderImpl to parse the additional device
state property. This is needed for devices who define their
device states in device_state_configuration.xml overlays (as
opposed to java-based configurations like
BookStyleDeviceStatePolicy.java)

Test: On Cuttlefish, run atest android.server.wm.jetpack.area.ExtensionRearDisplayTest#testRearDisplayStatusListeners
Fixes: 379780843
Bug: 372486634

Flag: EXEMPT bugfix
Change-Id: I03393ae40321ef79f403c78035f0d31493496cf9