Merge "Add CTS tests for user agent." am: 0ba615423c am: de25b94d5d am: dfe9d5944c

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2470103

Change-Id: I8ce5045e5a49db435399b45144460c9dc6e1d425
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>