input_interpreter: Fix button hold being interpreted incorrectly on init

We reset all the button states to 0 except the first index (which has all the buttons as pressed) to prevent a button hold being interpreted as a button that was pressed once on the first poll.

src/core/frontend/input_interpreter.h

@@ -66,6 +66,9 @@ public:
     /// Gets a button state from HID and inserts it into the array of button states.
     void PollInput();
 
+    /// Resets all the button states to their defaults.
+    void ResetButtonStates();
+
     /**
      * Checks whether the button is pressed.
      *