Rename existing getSensorProperties, prepare for TestApi

Parcelables cannot easily become TestApi, since CREATOR, etc
all come as extra baggage. So, rename internal usage to
*SensorPropertiesInternal, and add a new class that exposes
only specific parts of the properties for future TestApi

Bug: 169459906
Test: Enroll, Auth on existing devices
Test: atest com.android.systemui.biometrics
Test: atest com.android.server.biometrics
Change-Id: I59ae6bd30bef0eccbbcb58ddd7fa443be8a42ccf