add a new telephony protection level

for oems which take telephony mainline module, all telephony related
apks will be signed with non-platform certificate. that said apks won't
be able to grant platform signature permission. Solution is to add a new
telephony protection level.

Bug: 141479803
Test: cts & manual
Change-Id: Ib3be016080d42fd76e7c131f4e44d815ce431e6e