Move the Robolectric shadow config up.

In my testing, this reduces the runtime of the Robolectric Settings test
suite on my Z840 workstation from 440 seconds to 402 seconds on average.
By avoiding having a method-level Robolectric shadow import, we avoid
going down a code path which needs to add more shadows later in the
Robolectric execution.

Bug: 64808827
Test: Settings robotests still pass
Change-Id: I7b40d73b30306ae3f9759281afbd7f7266579e24

tests/robotests/src/com/android/settings/DeviceInfoSettingsTest.java

@@ -45,7 +45,11 @@ import org.robolectric.annotation.Config;
 import java.util.List;
 
 @RunWith(SettingsRobolectricTestRunner.class)
-@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+@Config(
+    manifest = TestConfig.MANIFEST_PATH,
+    sdk = TestConfig.SDK_VERSION,
+    shadows = ShadowUtils.class
+)
 public class DeviceInfoSettingsTest {
 
     @Mock(answer = Answers.RETURNS_DEEP_STUBS)
@@ -83,7 +87,6 @@ public class DeviceInfoSettingsTest {
     }
 
     @Test
-    @Config(shadows = ShadowUtils.class)
     public void testNonIndexableKeys_existInXmlLayout() {
         final Context context = RuntimeEnvironment.application;
         final List<String> niks = DeviceInfoSettings.SEARCH_INDEX_DATA_PROVIDER