Fix PrefCategory layout to align text with actionbar title

Change-Id: I2716a92e2802e3ff01d4e550dae96e689d4370ff
Fix: 38011653
Test: visual

res/layout/preference_category_material_settings.xml

@@ -43,7 +43,7 @@
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:paddingStart="60dp"
+        android:paddingStart="56dp"
         android:orientation="vertical">
         <TextView
             android:id="@android:id/title"

res/xml/display_settings.xml

@@ -119,7 +119,7 @@
     <ListPreference
         android:key="theme"
         android:title="@string/device_theme"
-        android:summary="%s" />
+        android:summary="@string/summary_placeholder" />
 
     <Preference
         android:key="vr_display_pref"

src/com/android/settings/display/ThemePreferenceController.java

@@ -13,8 +13,6 @@
  */
 package com.android.settings.display;
 
-import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.ACTION_THEME;
-
 import android.content.Context;
 import android.content.om.IOverlayManager;
 import android.content.om.OverlayInfo;
@@ -39,6 +37,8 @@ import libcore.util.Objects;
 import java.util.ArrayList;
 import java.util.List;
 
+import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.ACTION_THEME;
+
 public class ThemePreferenceController extends PreferenceController implements
         Preference.OnPreferenceChangeListener {
 
@@ -94,6 +94,7 @@ public class ThemePreferenceController extends PreferenceController implements
             theme = mContext.getString(R.string.default_theme);
             pref.setSummary(theme);
         }
+        pref.setSummary(theme);
         pref.setValue(theme);
     }