Idle: add voice announcement (user configurable).

Fixes of #1174

src/main/java/de/dennisguse/opentracks/settings/AnnouncementsSettingsFragment.java

@@ -17,7 +17,7 @@ public class AnnouncementsSettingsFragment extends PreferenceFragmentCompat {
     @Override
     public void onStart() {
         super.onStart();
-        ((SettingsActivity) getActivity()).getSupportActionBar().setTitle(R.string.settings_announcements_title);
+        ((SettingsActivity) getActivity()).getSupportActionBar().setTitle(R.string.settings_announcements_statistics_title);
     }
 
     @Override

src/main/java/de/dennisguse/opentracks/settings/PreferencesUtils.java

@@ -312,6 +312,10 @@ public class PreferencesUtils {
         return getBoolean(R.string.voice_on_device_speaker_key, DEFAULT);
     }
 
+    public static boolean shouldVoiceAnnouncementIdle() {
+        return getBoolean(R.string.voice_announce_idle_key, true);
+    }
+
     public static Duration getVoiceAnnouncementFrequency() {
         final int DEFAULT = Integer.parseInt(resources.getString(R.string.voice_announcement_frequency_default));
         int value = getInt(R.string.voice_announcement_frequency_key, DEFAULT);