a11y: Clean up TestDialogHelper for magnification tests

This moves TestDialogHelper to a separate file, and cleans up a couple
of magnification tests.

Bug: b/397530196
Flag: EXEMPT refactor
Test: SettingsRoboTests:com.android.settings.accessibility.MagnificationModePreferenceControllerTest &&
      SettingsRoboTests:com.android.settings.accessibility.MagnificationCursorFollowingModePreferenceControllerTest
Change-Id: I68e70061b84dacacf95bc05c784677b8d9794754

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

@@ -19,7 +19,6 @@ package com.android.settings.accessibility;
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertWithMessage;
 
-import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.provider.Settings;
@@ -28,13 +27,11 @@ import android.text.TextUtils;
 import android.widget.AdapterView;
 import android.widget.ListView;
 
-import androidx.annotation.NonNull;
 import androidx.preference.Preference;
 import androidx.preference.PreferenceManager;
 import androidx.preference.PreferenceScreen;
 import androidx.test.core.app.ApplicationProvider;
 
-import com.android.settings.DialogCreatable;
 import com.android.settings.R;
 import com.android.settings.accessibility.MagnificationCursorFollowingModePreferenceController.ModeInfo;
 
@@ -179,22 +176,4 @@ public class MagnificationCursorFollowingModePreferenceControllerTest {
         assertThat(TextUtils.equals(mController.getSummary(), mContext.getString(
                 R.string.accessibility_magnification_cursor_following_edge))).isTrue();
     }
-
-    private static class TestDialogHelper implements DialogHelper {
-        private DialogCreatable mDialogDelegate;
-        private Dialog mDialog;
-
-        @Override
-        public void showDialog(int dialogId) {
-            mDialog = mDialogDelegate.onCreateDialog(dialogId);
-        }
-
-        public void setDialogDelegate(@NonNull DialogCreatable delegate) {
-            mDialogDelegate = delegate;
-        }
-
-        public Dialog getDialog() {
-            return mDialog;
-        }
-    }
 }

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

@@ -23,7 +23,6 @@ import static com.google.common.truth.Truth.assertThat;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 
-import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.os.Bundle;
@@ -35,13 +34,11 @@ import android.widget.AdapterView;
 import android.widget.ListView;
 import android.widget.TextView;
 
-import androidx.annotation.NonNull;
 import androidx.preference.Preference;
 import androidx.preference.PreferenceManager;
 import androidx.preference.PreferenceScreen;
 import androidx.test.core.app.ApplicationProvider;
 
-import com.android.settings.DialogCreatable;
 import com.android.settings.R;
 import com.android.settings.accessibility.AccessibilityDialogUtils.DialogEnums;
 import com.android.settings.accessibility.MagnificationCapabilities.MagnificationMode;
@@ -258,33 +255,4 @@ public class MagnificationModePreferenceControllerTest {
         mController.onCreate(savedInstanceState);
         mController.displayPreference(mScreen);
     }
-
-    private static class TestDialogHelper implements DialogCreatable, DialogHelper {
-        private DialogCreatable mDialogDelegate;
-        private Dialog mDialog;
-
-        @Override
-        public void showDialog(int dialogId) {
-            mDialog = onCreateDialog(dialogId);
-        }
-
-        public void setDialogDelegate(@NonNull DialogCreatable delegate) {
-            mDialogDelegate = delegate;
-        }
-
-        @NonNull
-        @Override
-        public Dialog onCreateDialog(int dialogId) {
-            return mDialogDelegate.onCreateDialog(dialogId);
-        }
-
-        @Override
-        public int getDialogMetricsCategory(int dialogId) {
-            return mDialogDelegate.getDialogMetricsCategory(dialogId);
-        }
-
-        public Dialog getDialog() {
-            return mDialog;
-        }
-    }
 }

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

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2025 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.accessibility;
+
+import android.app.Dialog;
+
+import androidx.annotation.NonNull;
+
+import com.android.settings.DialogCreatable;
+
+public class TestDialogHelper implements DialogHelper {
+    private DialogCreatable mDialogDelegate;
+    private Dialog mDialog;
+
+    @Override
+    public void showDialog(int dialogId) {
+        mDialog = mDialogDelegate.onCreateDialog(dialogId);
+    }
+
+    public void setDialogDelegate(@NonNull DialogCreatable delegate) {
+        mDialogDelegate = delegate;
+    }
+
+    public Dialog getDialog() {
+        return mDialog;
+    }
+}