Rename SDK_VERSION_O to SDK_VERSION

Test: make RunSettingsRoboTests -j40
Change-Id: I6715062d8addadda441e32809db1af55f15e3a90

tests/robotests/src/com/android/settings/widget/RingProgressBarTest.java

@@ -31,7 +31,7 @@ import org.robolectric.annotation.Config;
 import static junit.framework.Assert.assertEquals;
 
 @RunWith(SettingsRobolectricTestRunner.class)
-@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION_O)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
 public class RingProgressBarTest {
 
     private Context mContext = RuntimeEnvironment.application;