telephony: pick correct APN for MSim

The subId should be sent to TelephonyProvider to pick the correct
preferred APN. Without it, the first APN will simply gets used.

For non-MSim, sending subId shouldn't break anything (Settings send
it anyway)

Change-Id: I837e33391b39bf9bc0b7af06840bfe899c6ffcb7
Merge pull request #2 from CyanogenMod/cm-12.0

telephony: pick correct APN for MSim