Add tests for resource flags

- Flags work, except all RW flags are treated as "enabled".
- Also enable tests that no longer need to be disabled
- Also added a java system prop that has the runtime directory
path

Bug: 396458006
Test: $ANDROID_BUILD_TOP/frameworks/base/ravenwood/scripts/run-ravenwood-tests.sh -s
Flag: EXEMPT host test change only

Change-Id: I0402da0ba59c27c17b6dd4d2f646cdee7800a290