Skip connectivity unit tests before S

The tests are packaged together with other tests in a common coverage
suite, so need to be individually annotated so that they are skipped
before S.

They do not need to pass on platforms older than S, because such
platforms will not updated with the code that is tested.

Bug: 187935317
Test: atest ConnectivityCoverageTests on R
Change-Id: I10da45ae023e7f1e8cd11ec857b84346892a3fa8

tests/unit/java/android/net/VpnManagerTest.java

@@ -27,9 +27,11 @@ import static org.mockito.Mockito.when;
 
 import android.content.ComponentName;
 import android.content.Intent;
+import android.os.Build;
 import android.test.mock.MockContext;
 import android.util.SparseArray;
 
+import androidx.test.filters.SdkSuppress;
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
@@ -43,6 +45,7 @@ import org.junit.runner.RunWith;
 /** Unit tests for {@link VpnManager}. */
 @SmallTest
 @RunWith(AndroidJUnit4.class)
+@SdkSuppress(minSdkVersion = Build.VERSION_CODES.S, codeName = "S")
 public class VpnManagerTest {
     private static final String PKG_NAME = "fooPackage";