Changes

pySim-shell: recognize ADP pins longer than 8 digits as hexadecimal

When a hexadecimal formatted ADM pin is retrieved via the
card_key_provider, it still requires the --pin-is-hex parameter so
that sanitize_pin_adm knows the correct format.

This unfortunately ruins the card_key_provider feature for all cards
that use hexadecimal pins, because the --pin-is-hex would also be
required in scripts, which makes a script either useable for cards
with hexadecimal ADM or for for cards with ASCII ADM.

To minimize the problem, let's recognize all ADM pins longer than 8
digits as hexadecimal in case --pin-is-hex is not set.

Related: OS#4348
Change-Id: Iad9398365d448946c499ce89e3cfb2c3af5d525e