Isolate Ravenwood sysprops from device sysprops

Now we use hardcoded sysprops for the most part.
We only pull in selected properties from build.prop.

Flag: EXEMPT host test change only
Bug: 377577035
Test: $ANDROID_BUILD_TOP/frameworks/base/ravenwood/scripts/run-ravenwood-tests.sh
Change-Id: I5ff27ab8123858c71ad2645448865d8cb081b250