Move @DisabledOnRavenwood logic to the runner side

Now the whole logic about "@DisabledOnRavenwood" is moved to the runner,
with "RUN_DISABLED_TESTS" support too.
RavenwoodRule is no longer needed to handle @DisabledOnRavenwood.

Also create test result stats files, which contains number of tests
passed/failed/skipped.

Bug: 356918135
Test: $ANDROID_BUILD_TOP/frameworks/base/ravenwood/scripts/run-ravenwood-tests.sh
Test: atest RavenwoodBivalentTest_device
Flag: EXEMPT host test change only

Change-Id: I8e1ee027e7cac9014cdc2b67b8f748b0922a536e