After some struggle I was able to abstract a method that I can call whenever I need to show or hide the keyboard without using the SHOW_FORCED that I saw in many answers where the result would be the keyboard open even on a new activity without text input.
I used this code inside onGlobalLayout to check if the keyboard is open or not and then in my method I decide if I want open or close.
Here is the code:
To check if it's open or not:
private static boolean isKeyboardVisible(Activity activity) {
    Rect r = new Rect();
    View contentView = activity.findViewById(android.R.id.content);
    contentView.getWindowVisibleDisplayFrame(r);
    int screenHeight = contentView.getRootView().getHeight();
    int keypadHeight = screenHeight - r.bottom;
    return (keypadHeight > screenHeight * 0.15);
}
To perform the action that I need (here is where I call the above method):
public static void toggleKeyboard(final Activity activity, final boolean showKeyboard) {
    final InputMethodManager imm =
            (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
    // The Handler is needed because the method that checks if the keyboard
    // is open need some time to get the updated value from the activity,
    // e.g. when my activity return to foreground. 
    new Handler().postDelayed(new Runnable() {
        public void run() {
            // This 'if' just check if my app still in foreground 
            // when the code is executed to avoid any problem.
            // I've leave out of the answer to keep short, you may use your own.
            if(Tools.isAppInForeground(activity)) {
                // Check the keyboard.
                boolean isVisible = isKeyboardVisible(activity);
                // If I want to show the keyboard and it's not visible, show it!
                if (showKeyboard && !isVisible) {
                    imm.toggleSoftInput(InputMethodManager.SHOW_IMPLICIT,
                            InputMethodManager.HIDE_IMPLICIT_ONLY);
                // If I want to hide and the keyboard is visible, hide it!
                } else if (!showKeyboard && isVisible) {
                    imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 0);
                }
            }
        }
    }, 100);
}
To use, I just call like this:
toggleKeyboard(myactivity, true); // show
// or
toggleKeyboard(myactivity, false); // hide