Swap settings and clear passphrase menu options

Android design pattern best practice recommends placing the settings
menu item below all other items because it's not frequently needed.

In that spirit, I've also moved the clear passphrase option to be first
since it is likely to be used more often than database import/export.

res/menu/text_secure_normal.xml

@@ -5,9 +5,9 @@
           android:icon="@drawable/ic_menu_msg_compose_holo_dark"
           android:showAsAction="ifRoom" />
 
-    <item android:title="@string/text_secure_normal__menu_settings"
+    <item android:title="@string/text_secure_normal__menu_clear_passphrase"
-          android:id="@+id/menu_settings"
+          android:id="@+id/menu_clear_passphrase"
-          android:icon="@android:drawable/ic_menu_preferences" />
+          android:icon="@android:drawable/ic_menu_close_clear_cancel" />
 
     <item android:title="@string/text_secure_normal__menu_import_export"
           android:icon="@android:drawable/ic_menu_save">
@@ -22,8 +22,8 @@
         </menu>
     </item>
 
-    <item android:title="@string/text_secure_normal__menu_clear_passphrase"
+    <item android:title="@string/text_secure_normal__menu_settings"
-          android:id="@+id/menu_clear_passphrase"
+          android:id="@+id/menu_settings"
-          android:icon="@android:drawable/ic_menu_close_clear_cancel" />
+          android:icon="@android:drawable/ic_menu_preferences" />
 
 </menu>