NFC: Allow HostApduService to indicate transaction unhandled.

This will cause the OS to show UI that allows the user to pick
another application that could potentially handle the transaction.

Also, tweak processCommandApdu() method to take a Bundle to be more
future-proof.

Bug: 10262585
Change-Id: If9d060341b472fac0349f539c04b87e85fe79dfb