Remove old migration from subId to ICCID

An old migration of phone account IDs from subIds to ICCIDs is causing
crashes. Since this migration was for L->M, we don't need it anymore so
I'm removing it.

Bug: 147408268
Test: manual telephony test suite
Change-Id: Ice45ef14546c2df2e5c2c2da8af8f83d7806a5b5
1 file changed