Fix cannot switch between multiple TTS engines

- We didn't reset reset radio button state when user click back
while dialog was popped. Change the UI, when user really accepts the
dialog content, then changes radio button state.
- Migrate TtsEnginePreferenceFragment to RadioButtonPickerFragment

Fixes: 135588938
Test: manual
Change-Id: Ia824e08d59c77a23e6590ff0f5b7d897a73a1ff8

tests/robotests/src/com/android/settings/testutils/shadow/ShadowTtsEngines.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2019 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.testutils.shadow;
+
+import android.content.Intent;
+import android.speech.tts.TextToSpeech;
+import android.speech.tts.TtsEngines;
+
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+import org.robolectric.annotation.Resetter;
+
+import java.util.List;
+import java.util.Locale;
+
+@Implements(TtsEngines.class)
+public class ShadowTtsEngines {
+    private static TtsEngines sInstance;
+
+    public static void setInstance(TtsEngines ttsEngines) {
+        sInstance = ttsEngines;
+    }
+
+    @Resetter
+    public static void reset() {
+        sInstance = null;
+    }
+
+    @Implementation
+    protected List<TextToSpeech.EngineInfo> getEngines() {
+        return sInstance.getEngines();
+    }
+
+    @Implementation
+    protected TextToSpeech.EngineInfo getEngineInfo(String packageName) {
+        return sInstance.getEngineInfo(packageName);
+    }
+
+    @Implementation
+    protected String getDefaultEngine() {
+        return sInstance.getDefaultEngine();
+    }
+
+    @Implementation
+    protected Intent getSettingsIntent(String engine) {
+        return sInstance.getSettingsIntent(engine);
+    }
+
+    @Implementation
+    protected boolean isEngineInstalled(String engine) {
+        return sInstance.isEngineInstalled(engine);
+    }
+
+    @Implementation
+    protected boolean isLocaleSetToDefaultForEngine(String engineName) {
+        return sInstance.isLocaleSetToDefaultForEngine(engineName);
+    }
+
+    @Implementation
+    protected Locale getLocalePrefForEngine(String engineName) {
+        return sInstance.getLocalePrefForEngine(engineName);
+    }
+
+    @Implementation
+    protected synchronized void updateLocalePrefForEngine(String engineName, Locale newLocale) {
+        sInstance.updateLocalePrefForEngine(engineName, newLocale);
+    }
+
+    @Implementation
+    protected Locale parseLocaleString(String localeString) {
+        return sInstance.parseLocaleString(localeString);
+    }
+}