Merge "Do not send empty TXT records" into main am: 141aac3b73

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3166637

Change-Id: I8f98d0bd883028d0359c522e9e2afc0ff55570c5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>