[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: 8a5ce02a -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: I67fe398cbae1b2a24fea521201d90fb4d93d7767