Restrict the BTLE examples to Low Energy use cases

This change vastely descreases the search time. There is no need to
perform a traditional SDP scan too.

Change-Id: I63d7e16dca77fb1b1db42bb330f91e917a9dd054
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

examples/bluetooth/heartlistener/heartrate.cpp

@@ -50,6 +50,7 @@ HeartRate::HeartRate():
 {
     //! [devicediscovery-1]
     m_deviceDiscoveryAgent = new QBluetoothDeviceDiscoveryAgent(this);
+    m_deviceDiscoveryAgent->setLowEnergyDiscoveryTimeout(5000);
 
     connect(m_deviceDiscoveryAgent, SIGNAL(deviceDiscovered(const QBluetoothDeviceInfo&)),
             this, SLOT(addDevice(const QBluetoothDeviceInfo&)));
@@ -73,7 +74,7 @@ void HeartRate::deviceSearch()
     qDeleteAll(m_devices);
     m_devices.clear();
     //! [devicediscovery-2]
-    m_deviceDiscoveryAgent->start();
+    m_deviceDiscoveryAgent->start(QBluetoothDeviceDiscoveryAgent::LowEnergyMethod);
     //! [devicediscovery-2]
     setMessage("Scanning for devices...");
 }

examples/bluetooth/lowenergyscanner/device.cpp

@@ -54,6 +54,7 @@ Device::Device():
 {
     //! [les-devicediscovery-1]
     discoveryAgent = new QBluetoothDeviceDiscoveryAgent();
+    discoveryAgent->setLowEnergyDiscoveryTimeout(5000);
     connect(discoveryAgent, SIGNAL(deviceDiscovered(const QBluetoothDeviceInfo&)),
             this, SLOT(addDevice(const QBluetoothDeviceInfo&)));
     connect(discoveryAgent, SIGNAL(error(QBluetoothDeviceDiscoveryAgent::Error)),
@@ -84,7 +85,7 @@ void Device::startDeviceDiscovery()
 
     setUpdate("Scanning for devices ...");
     //! [les-devicediscovery-2]
-    discoveryAgent->start();
+    discoveryAgent->start(QBluetoothDeviceDiscoveryAgent::LowEnergyMethod);
     //! [les-devicediscovery-2]
 
     if (discoveryAgent->isActive()) {