Fixed GUI Input Mapping Demo Script Errors for 4.0-dev

Edited the project settings to match the new Godot 4 standard and fixed
the script errors which were making it impossible to run this demo.

Now everything works properly for the 4.0-dev version.

Changed to Vulkan Mobile + Changed argument name

Followed the suggestions of aaronfranke
Changed viewport size

gui/input_mapping/ActionRemapButton.gd

@@ -8,9 +8,9 @@ func _ready():
 	display_current_key()
 
 
-func _toggled(button_pressed):
-	set_process_unhandled_key_input(button_pressed)
-	if button_pressed:
+func _toggled(is_button_pressed):
+	set_process_unhandled_key_input(is_button_pressed)
+	if is_button_pressed:
 		text = "... Key"
 		release_focus()
 	else:
@@ -21,7 +21,7 @@ func _unhandled_key_input(event):
 	# Note that you can use the _input callback instead, especially if
 	# you want to work with gamepads.
 	remap_action_to(event)
-	pressed = false
+	button_pressed = false
 
 
 func remap_action_to(event):
@@ -31,5 +31,5 @@ func remap_action_to(event):
 
 
 func display_current_key():
-	var current_key = InputMap.get_action_list(action)[0].as_text()
+	var current_key = InputMap.action_get_events(action)[0].as_text()
 	text = "%s Key" % current_key