Fix EuiccCard's IMEI encoding.

According to SGP.22 v2.1+, the IMEI encoding scheme is different than
normal BCD. We include behavior for both 2.1+ as well as pre-2.1.

This fix is targeted for Q, and we should offer this as a patch to OEMs
if necessary before then.

Bug: 113071724
Change-Id: I6865d76a545b5418394674374f33e5de4fc986bd
Fix: 113071724
Test: atest FrameworksTelephonyTests