[automerger skipped] Fixed dangling network agent not cleaned up am:...

[automerger skipped] Fixed dangling network agent not cleaned up am: 308ef12e am: 760317aa -s ours

am skip reason: Change-Id I6fcf1895964f66ef1095f62475fb856b10ce4948 with SHA-1 ec05e7f2 is in history

Original change: https://android-review.googlesource.com/c/platform/frameworks/opt/telephony/+/1369564

Change-Id: Iba97a564e81f3c2bdd58eb4c98011a58bb321704