use mvp pattern for system contact card

OpenKeychain/src/main/res/layout/system_contact_card.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:orientation="vertical">
+
+    <TextView
+        style="@style/CardViewHeader"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/section_linked_system_contact" />
+
+    <LinearLayout
+        android:id='@+id/system_contact_layout'
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:background="?android:selectableItemBackground"
+        android:orientation="horizontal">
+
+        <ImageView
+            android:id="@+id/system_contact_picture"
+            android:layout_width="48dp"
+            android:layout_height="48dp"
+            android:layout_margin="6dp"
+            android:scaleType="centerCrop"
+            tools:src="@drawable/ic_person_grey_48dp" />
+
+        <TextView
+            android:id="@+id/system_contact_name"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_vertical"
+            tools:text="@string/view_key_fragment_no_system_contact"
+            android:textAppearance="?android:attr/textAppearanceMedium" />
+    </LinearLayout>
+
+</LinearLayout>