Allow appending static preferences to RadioButtonPickerFragment

This makes it so that static preferences can also be added after
the candidates so they can show up on the bottom of the screen.
This is done via a new xml tag for the preference screen that
is usually mostly empty that RaiodButtonPickerFragments use

Test: robotests
Bug: 111450127
Change-Id: I0fe2f480f0ff59b9bf9269e94b33ab4b008b47b8

tests/robotests/src/com/android/settings/widget/RadioButtonPickerFragmentTest.java

@@ -18,6 +18,7 @@ package com.android.settings.widget;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
@@ -37,7 +38,9 @@ import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Answers;
+import org.mockito.InOrder;
 import org.mockito.Mock;
+import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
 import org.robolectric.RuntimeEnvironment;
 
@@ -98,6 +101,26 @@ public class RadioButtonPickerFragmentTest {
         assertThat(mFragment.setDefaultKeyCalled).isTrue();
     }
 
+    @Test
+    public void staticPreferencesPrepended_addedFirst() {
+        mFragment.mAppendStaticPreferences = false;
+        mFragment.updateCandidates();
+
+        InOrder inOrder = Mockito.inOrder(mFragment);
+        inOrder.verify(mFragment).addStaticPreferences(any());
+        inOrder.verify(mFragment).getRadioButtonPreferenceCustomLayoutResId();
+    }
+
+    @Test
+    public void staticPreferencesAppended_addedLast() {
+        mFragment.mAppendStaticPreferences = true;
+        mFragment.updateCandidates();
+
+        InOrder inOrder = Mockito.inOrder(mFragment);
+        inOrder.verify(mFragment).mayCheckOnlyRadioButton();
+        inOrder.verify(mFragment).addStaticPreferences(any());
+    }
+
     @Test
     public void shouldHaveNoCustomPreferenceLayout() {
         assertThat(mFragment.getRadioButtonPreferenceCustomLayoutResId()).isEqualTo(0);