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

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

Change-Id: Ib84efceff6cdf58012586358220c74bd3528a654
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>