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

res/xml/firmware_version.xml

@@ -28,7 +28,6 @@
         android:title="@string/firmware_version"
         android:summary="@string/summary_placeholder"
         settings:enableCopying="true"
-        settings:allowDynamicSummaryInSlice="true"
         settings:controller="com.android.settings.deviceinfo.firmwareversion.FirmwareVersionDetailPreferenceController"/>
 
     <!-- Security patch -->
@@ -68,7 +67,6 @@
         android:title="@string/build_number"
         android:summary="@string/summary_placeholder"
         settings:enableCopying="true"
-        settings:allowDynamicSummaryInSlice="true"
         settings:controller="com.android.settings.deviceinfo.firmwareversion.SimpleBuildNumberPreferenceController"/>
 
 </PreferenceScreen>