Add sample data and various tools attributes to layouts

Author: cketti

app/k9mail/src/main/res/layout/activity_unread_widget_configuration.xml

@@ -1,8 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:orientation="vertical">
+    android:orientation="vertical"
+    tools:context=".widget.unread.UnreadWidgetConfigurationActivity">
 
     <include layout="@layout/toolbar" />
 

app/ui/legacy/sampledata/accounts.json

@@ -0,0 +1,19 @@
+{
+  "data": [
+    {
+      "name": "Personal",
+      "email": "user@domain.example",
+      "color": "#FF1976D2"
+    },
+    {
+      "name": "Work",
+      "email": "firstname.lastname@work.example",
+      "color": "#FFE91E63"
+    },
+    {
+      "name": "Club",
+      "email": "name@sportsclub.example",
+      "color": "#FFFFB300"
+    }
+  ]
+}