Convert xml based API allowDynamicSummaryInSlice to java

- Add boolean useDynamicSliceSummary() in Sliceable interface. This is
  the switch equivalent to android:allowDynamicSummaryInSlice in xml. It
  moves the setter closer to regular Sliceable APIs, thus less easily to
  miss.
- Coverted all android:allowDynamicSummaryInSlice to use the java API.
  - Except 2 prefs in my_device_info. They incorrectly set this to true
  previously (controller is not sliceable, no point setting
  dynamicSliceSummary to true. They just won't do anything)

Fixes: 128446156
Test: robolectric
Change-Id: Ic57acd590dec3e87dcf4592df137321d14b854d9

src/com/android/settings/notification/MediaVolumePreferenceController.java

@@ -22,8 +22,7 @@ import android.text.TextUtils;
 
 import com.android.settings.R;
 
-public class MediaVolumePreferenceController extends
-    VolumeSeekBarPreferenceController {
+public class MediaVolumePreferenceController extends VolumeSeekBarPreferenceController {
 
     private static final String KEY_MEDIA_VOLUME = "media_volume";
 
@@ -43,6 +42,11 @@ public class MediaVolumePreferenceController extends
         return TextUtils.equals(getPreferenceKey(), KEY_MEDIA_VOLUME);
     }
 
+    @Override
+    public boolean useDynamicSliceSummary() {
+        return true;
+    }
+
     @Override
     public String getPreferenceKey() {
         return KEY_MEDIA_VOLUME;