Add OEM_PAID and OEM_PRIVATE Apn types

Bug: 366194627
Test: m
Test: manually add oem_paid APN to telephony.db and verify OEM_PAID
      network capability in adb shell dumpsys connectivity
Flag: com.android.internal.telephony.flags.oem_paid_private
Change-Id: Ib5af475115be1c4f110e91163fc21297556ad22c