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

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

Change-Id: I9fb6c76d7ce39e9f49d0419b3b2ed930b1419562