ui/trinary_input_char: remove some special chars
As they are not legible enough in the current arial 9x9 font.
@ and ^ are switched so ^ is more legible and [ ] { } align better.
static char _alphabet_uppercase[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
static char _alphabet_lowercase[] = "abcdefghijklmnopqrstuvwxyz";
static char _digits[] = "0123456789";
-static char _special_chars[] = " !\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~";
+// ` and ~ are missing here as they don't legible on the device with arial 9x9. Can add them back
+// after tuning the font.
+static char _special_chars[] = " !\"#$%&'()*+,-./:;<=>?^[\\]@_{|}";
typedef struct {
// Can be NULL.
