Merge "Introduce SIP message validation for SIP Delegates (1/2)" am: 33305bb3fd am: c338c769a2 am: 9cbc5ed9f8

Original change: https://android-review.googlesource.com/c/platform/packages/services/Telephony/+/1646653

Change-Id: I5163bb85e9ee5998207a392753bb484c6941936c