create a new notification channel for high prio sim alert

create a high priority notification channel for sim releated alert
in some scenario, we want users to know that they cannot completely
rely on their ability to make a phone call and data call with the
SIM and this may apply to emergency situations.

Bug: 134790138
Test: Manual test
Change-Id: I312383efa36042fe8d2b89a1800fc3e5b856ba32