simple-agent: Enable bluetooth technology.

We can't to anything with bluetooth until its enabled via connman
(otherwise everything else will blocked/soft rfkilled).

Enable it explicitely in the agent so the user doesn't have to first use
connmanctl.

Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D2209

bluez/simple-agent

@@ -58,6 +58,29 @@ if __name__ == '__main__':
         mainloop.quit()
 
     bus = dbus.SystemBus()
+
+    connman_bt_tech = dbus.Interface(
+        bus.get_object("net.connman", "/net/connman/technology/bluetooth"),
+        "net.connman.Technology")
+
+    def property_changed(name, value):
+        if name == "Powered" and value:
+            print("Bluetooth powered on")
+        mainloop.quit()
+
+    # Enable the connman bluetooth technology so that connman removes its
+    # rfkill on the bluetooth adaptors
+    match = connman_bt_tech.connect_to_signal("PropertyChanged",
+            property_changed)
+    try:
+        connman_bt_tech.SetProperty("Powered", True)
+        mainloop.run()
+    except dbus.DBusException as e:
+        if e.get_dbus_name() != "net.connman.Error.AlreadyEnabled":
+            raise(e)
+    finally:
+        match.remove()
+
     manager = dbus.Interface(bus.get_object("org.bluez", "/"),
                              "org.freedesktop.DBus.ObjectManager")
     agent_manager_iface = dbus.Interface(bus.get_object('org.bluez',