Refactor CaptionAppearanceFragment to improve maintainability (4/n)

Root cause: There is a bunch of different logic of preferences in CaptionAppearanceFragment. It’s hard to implement new features and hard to maintain and hard to be testable.
Solution: Move out preset preference logic of CaptionAppearanceFragment into controllers to reduce the complexity of the relationship between preference and fragment.

Bug: 197695932
Test: make RunSettingsRoboTests ROBOTEST_FILTER=CaptionPresetControllerTest CaptionAppearanceFragmentTest
Change-Id: I5409c1e8a6bdfc633abc304d8cf800ea0943de78

tests/robotests/src/com/android/settings/accessibility/CaptionHelperTest.java

@@ -24,6 +24,7 @@ import static com.google.common.truth.Truth.assertThat;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import android.content.ContentResolver;
 import android.content.Context;
 import android.provider.Settings;
 import android.view.View;
@@ -61,12 +62,14 @@ public class CaptionHelperTest {
     private View mPreviewWindow;
     @Spy
     private final Context mContext = ApplicationProvider.getApplicationContext();
+    private ContentResolver mContentResolver;
     private CaptionHelper mCaptionHelper;
 
     @Before
     public void setUp() {
         when(mContext.getSystemService(CaptioningManager.class)).thenReturn(mCaptioningManager);
         mCaptionHelper = new CaptionHelper(mContext);
+        mContentResolver = mContext.getContentResolver();
     }
 
     @Test
@@ -170,4 +173,13 @@ public class CaptionHelperTest {
         final int edgeType = mCaptionHelper.getEdgeType();
         assertThat(edgeType).isEqualTo(CaptionStyle.EDGE_TYPE_OUTLINE);
     }
+
+    @Test
+    public void setRawUserStyle_shouldReturnSpecificStyle() {
+        mCaptionHelper.setRawUserStyle(CaptionStyle.PRESET_CUSTOM);
+
+        final int style = Settings.Secure.getInt(mContentResolver,
+                Settings.Secure.ACCESSIBILITY_CAPTIONING_PRESET, 0);
+        assertThat(style).isEqualTo(CaptionStyle.PRESET_CUSTOM);
+    }
 }