Config the number of live modems based on current multisim number. am: 400ce4ff76 am: 4136d05ffe am: 0c42690c19

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/15924337

Change-Id: I2cbf76e20c1672072b2e17ec4759dc0d7ecb7525