[Ravenwood] Cleanup and update RavenwoodEnvironment

- Move the UID/PID/targetSdk injection into RavenwoodRuntimeState
- Update VMRuntime to return the configured target SDK level
- Remove the Workaround class in RavenwoodEnvironment
- Implement Os.gettid to make Process.myTid return a real value

Flag: EXEMPT host test change only
Bug: 292141694
Test: $ANDROID_BUILD_TOP/frameworks/base/ravenwood/scripts/run-ravenwood-tests.sh
Change-Id: I611a6cde7c7fb53f71a7a25e93143f4884af734b