Config the number of live modems based on current multisim number. am: 400ce4ff am: a720f213 am: 7305c8bd

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

Change-Id: Ie1b73627f2f29e29c85e88aff49d115a7e15a778