Disable StrictModeTest

- The test was failing because the target method isn't enabled on Ravenwood.
- Even if we keep the target method, it'd still fail because it touches the static field
    which isn't initialized.

- Given most StrictMode methods aren't enabled and we don't even enable CTS on it,
    let's diable the whole test.

Fix: 412485208
Test: atest FrameworksCoreTestsRavenwood:android.os.StrictModeTest
Flag: EXEMPT test change only
Change-Id: Ibc89be156a8c17ccb04abe2f2e5226b072083a09