Revert "Don't use framework strings for formatting file sizes"

This reverts commit ded99003c4.

- Add java import in order to build successfully
- Fix RunSettingsRoboTests

Test: adb shell am instrument -w -e class
com.android.settings.utils.FileSizeFormatterTest
com.android.settings.tests.unit/android.support.test.runner.AndroidJUnitRunner
Test: make -j RunSettingsRoboTests
Bug: 70005649
Bug: 36994779
Change-Id: I1c0ff48c749e9fbb82fd670c27243bd3922ed373

tests/robotests/src/com/android/settings/deviceinfo/storage/StorageItemPreferenceControllerTest.java

@@ -92,6 +92,8 @@ public class StorageItemPreferenceControllerTest {
     @Before
     public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
+        SettingsShadowResources.overrideResource("android:string/fileSizeSuffix", "%1$s %2$s");
+        SettingsShadowResources.overrideResource("android:string/gigabyteShort", "GB");
         when(mFragment.getActivity()).thenReturn(mActivity);
         when(mFragment.getFragmentManager()).thenReturn(mFragmentManager);
         when(mFragmentManager.beginTransaction()).thenReturn(mFragmentTransaction);