Currently, when the hamburger menu, or the 3-dot menu is open, the Android “back” (<) button closes the doc. That’s not really what I expect to happen. I would expect it to just close the menu.
Suggestion: When a menu is open, the Android “back” button should have the same action as the 3-dot menu’s “cancel” option and the the hamburger menu’s “back” arrow.
BTW, for consistency, shouldn’t both menus have the same close action (either “cancel”, or the back arrow)?