Slices feature supports device model.

- Migrate DeviceModelPreferenceController to BasePreferenceController
- Because Slice feature enables strict mode,
  we can't do I/O(DeviceInfoUtils.getMsvSuffix) on main thread.

  Using FutureTask to get around the foreground thread restriction.

- Modify test case for new device model controller.

Test: slice uri > content://android.settings.slices/intent/my_device_model
Test: make RunSettingsRoboTests -j
      atest UniquePreferenceTest SettingsGatewayTest

Change-Id: Idafc132dfa14138ad5a7edd58e63c4b0f644c994

res/xml/device_info_settings.xml

@@ -38,11 +38,12 @@
 
     <!-- Model & hardware -->
     <Preference
-        android:key="device_model"
+        android:key="device_model_v1"
         android:order="21"
         android:title="@string/hardware_info"
         settings:keywords="@string/keywords_model_and_hardware"
-        android:summary="@string/summary_placeholder" />
+        android:summary="@string/summary_placeholder"
+        settings:controller="com.android.settings.deviceinfo.DeviceModelPreferenceController" />
 
     <!-- IMEI -->
     <Preference

res/xml/my_device_info.xml

@@ -87,7 +87,9 @@
         android:order="21"
         android:title="@string/hardware_info"
         settings:keywords="@string/keywords_model_and_hardware"
-        android:summary="@string/summary_placeholder"/>
+        android:summary="@string/summary_placeholder"
+        settings:controller=
+            "com.android.settings.deviceinfo.DeviceModelPreferenceController" />
 
     <!-- IMEI -->
     <Preference