Fix sentence capitalization of locale names.

It turns out that out previous CL [1] is not sufficient to address all
the requests regarding capitalization.

With [1], now InputMethodSubtype#getLocaleDisplayName() returns a locale
name whose capitalization is basically optimized to be used as a list
item.  It works well for list UI, but on a UI element that looks like a
sentence text, we still need to capitalize the first character.

This CL takes care of those UI elements in the Settings app.  This CL
also addresses a remaining TODO about locale-unaware text formatting by
using about android.icu.text.ListFormatter.

  [1]: If105082ce703db7a86738455db7e9fb37f3c6fe8
       e489baf96df2837a3a63b626d9023a4a8b322c28

Bug: 29035638
Change-Id: I59f93f0bc067cdd87c6065c972a7da3cde1128f9

src/com/android/settings/inputmethod/InputMethodPreference.java

@@ -39,7 +39,6 @@ import com.android.settingslib.RestrictedLockUtils;
 import com.android.settingslib.RestrictedSwitchPreference;
 
 import java.text.Collator;
-import java.util.ArrayList;
 import java.util.List;
 
 import static com.android.settingslib.RestrictedLockUtils.EnforcedAdmin;
@@ -213,17 +212,10 @@ class InputMethodPreference extends RestrictedSwitchPreference implements OnPref
     }
 
     private String getSummaryString() {
-        final Context context = getContext();
         final InputMethodManager imm = getInputMethodManager();
         final List<InputMethodSubtype> subtypes = imm.getEnabledInputMethodSubtypeList(mImi, true);
-        final ArrayList<CharSequence> subtypeLabels = new ArrayList<>();
-        for (final InputMethodSubtype subtype : subtypes) {
-            final CharSequence label = subtype.getDisplayName(
-                  context, mImi.getPackageName(), mImi.getServiceInfo().applicationInfo);
-            subtypeLabels.add(label);
-        }
-        // TODO: A delimiter of subtype labels should be localized.
-        return TextUtils.join(", ", subtypeLabels);
+        return InputMethodAndSubtypeUtil.getSubtypeLocaleNameListAsSentence(
+                subtypes, getContext(), mImi);
     }
 
     private void showSecurityWarnDialog(final InputMethodInfo imi) {