Fix crash when importing contacts from SIM in Contacts app

The RIL_UNSOL_PCO_DATA case will be executed unintentionally after the RIL_UNSOL_RESPONSE_ADN_RECORDS case. Add a missing break at the end of the RIL_UNSOL_RESPONSE_ADN.

Error log:
AndroidRuntime: FATAL EXCEPTION: main
AndroidRuntime: Process: com.android.phone, PID: 6275
AndroidRuntime: java.lang.ClassCastException: com.android.internal.telephony.uicc.SimPhoneBookAdnRecord[] cannot be cast to android.telephony.PcoData

This was supposed to be in the 7.1.0_r4 merge but was missed out in ours.
Google adds it in the commit 4b4d80db.

Change-Id: Icfe1b77521eb8323934755b554ce6e510451f8bf