Well, actually there is a way to configure the behavior of the camera button but the options are very limited and hidden in a settings page I discovered using the Activity Launcher app; following is the procedure to open that settings page:
- open Activity Launcher and select “All activities” on the top of the page;
- scroll down until you find the app named “ProgrammableButton” tap on it and long-tap on the activity name, then select “Create shortcut”;
- a new shortcut will be created on the desktop, tap on it and a window will open in which there’s a list of possible actions you can assign to the camera button;
You can test immediately the behavior of the selected action (displayed on top of the list of actions) by selecting the action you want to try and then push the button for more than a second until you feel a vibration, then the action will be executed 
Bye! 