Imporve UI of system langauge list

Bug: b/274721595
Test: Manual test
Change-Id: I951de80de4ac40df48829d3f23c0f1c8d98e0137

res/layout/locale_drag_cell.xml

@@ -16,12 +16,13 @@
 
 <com.android.settings.localepicker.LocaleDragCell
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:minHeight="?android:listPreferredItemHeight"
     android:background="?android:colorBackground"
-              android:layout_marginTop="4dp"
+    android:layout_marginTop="12dp"
-              android:layout_marginBottom="4dp"
+    android:layout_marginBottom="12dp"
     android:layoutDirection="locale"
     android:textDirection="locale">
 
@@ -29,7 +30,9 @@
         android:id="@+id/checkbox"
         style="@style/LanguageCheckboxAndLabel"
         android:paddingStart="24dp"
-        android:layout_toStartOf="@+id/dragHandle"/>
+        android:layout_toStartOf="@+id/dragHandle"
+        android:layout_alignTop="@+id/miniLabel"
+        android:layout_alignBottom="@+id/miniLabel" />
 
     <TextView
         android:id="@+id/miniLabel"
@@ -38,16 +41,22 @@
         android:textColor="?android:attr/colorAccent"
         android:minWidth="24sp"
         android:gravity="center_vertical|center_horizontal"
-        android:layout_alignTop="@id/checkbox"
+        android:layout_centerVertical="true"/>
-        android:layout_alignBottom="@id/checkbox"/>
 
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:minHeight="?android:listPreferredItemHeight"
+        android:paddingStart="56dp"
+        android:layout_toStartOf="@+id/dragHandle">
         <LinearLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:orientation="vertical"
-        android:minHeight="?android:listPreferredItemHeight"
+            app:layout_constraintStart_toStartOf="parent"
-        android:paddingStart="56dp"
+            app:layout_constraintTop_toTopOf="parent"
-        android:layout_toStartOf="@+id/dragHandle">
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintBottom_toBottomOf="parent">
             <TextView
                 android:id="@+id/label"
                 style="@style/LanguageCheckboxAndLabel" />
@@ -57,7 +66,7 @@
                 style="@style/LanguageCheckboxAndLabel"
                 android:textAppearance="?android:attr/textAppearanceListItemSecondary"
                 android:textColor="?android:textColorSecondary"
-            android:layout_marginBottom="4dp"
+                android:layout_marginTop="4dp"
                 android:text="@string/locale_not_translated"/>
 
             <TextView
@@ -65,10 +74,11 @@
                 style="@style/LanguageCheckboxAndLabel"
                 android:textAppearance="?android:attr/textAppearanceListItemSecondary"
                 android:textColor="?android:textColorSecondary"
-            android:layout_marginBottom="4dp"
+                android:layout_marginTop="4dp"
                 android:text="@string/desc_current_default_language"/>
 
         </LinearLayout>
+    </androidx.constraintlayout.widget.ConstraintLayout>
 
     <ImageView
         android:id="@+id/dragHandle"
@@ -80,13 +90,6 @@
         android:src="@drawable/drag_handle"
         android:importantForAccessibility="no"
         android:layout_alignParentEnd="true"
-        android:layout_alignTop="@id/checkbox"
+        android:layout_centerVertical="true"/>
-        android:layout_alignBottom="@id/checkbox"/>
-
-    <View
-        android:layout_width="match_parent"
-        android:layout_height="1dp"
-        android:background="?android:attr/listDivider"
-        android:layout_alignParentBottom="true"/>
 
 </com.android.settings.localepicker.LocaleDragCell>

res/values/strings.xml

@@ -368,7 +368,7 @@
     <string name="desc_notice_of_language_picker">To select a language for each app, go to app language settings.</string>
 
     <!-- Title for locale helper page [CHAR LIMIT=NONE] -->
-    <string name="desc_locale_helper_footer_general">Learn more about languages</string>
+    <string name="desc_locale_helper_footer_general">Learn more about app languages</string>
 
     <!-- Link for Locale helper page. [CHAR LIMIT=NONE]-->
     <string name="link_locale_picker_footer_learn_more" translatable="false">https://support.google.com/android?p=per_language_app_settings</string>

src/com/android/settings/localepicker/LocaleDragAndDropAdapter.java

@@ -165,7 +165,7 @@ class LocaleDragAndDropAdapter
 
         dragCell.setLabelAndDescription(label, description);
         dragCell.setLocalized(feedItem.isTranslated());
-        dragCell.setCurrentDefault(feedItem.getLocale().equals(Locale.getDefault()));
+        dragCell.setCurrentDefault(feedItem.getLocale().equals(LocalePicker.getLocales().get(0)));
         dragCell.setMiniLabel(mNumberFormatter.format(i + 1));
         dragCell.setShowCheckbox(mRemoveMode);
         dragCell.setShowMiniLabel(!mRemoveMode);