protected void onServerReady(@NonNull final BluetoothGattServer server) {
		// Don't call super.onServerReady(server) when overriding this method.
		requestHandler.onServerReady(server);
	}
In this method the manager should get references to server characteristics and descriptors
that will use. The method is called after the service discovery of a remote device has
finished and {@link #isRequiredServiceSupported(BluetoothGatt)} returned true.
<p>
The references obtained in this method should be released in {@link #onServicesInvalidated()}.
<p>
This method is called only when the server was set by
{@link BleManager#useServer(BleServerManager)} and opened using {@link BleServerManager#open()}.

@param server The GATT Server instance. Use {@link BluetoothGattServer#getService(UUID)} to
              obtain service instance.
ble/src/main/java/no/nordicsemi/android/ble/BleManager.java