action encrypt to contact in view and multi select

OpenPGP-Keychain/res/layout/key_view_activity.xml

@@ -113,4 +113,17 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content" />
 
+    <TextView
+        style="@style/SectionHeader"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:padding="4dp"
+        android:text="@string/section_actions" />
+
+    <Button
+        android:id="@+id/action_encrypt"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/key_view_action_encrypt" />
+
 </LinearLayout>