Merge "Improve error message when testing network factory" am: e8cd6e4f am: 324e0f16

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1531798

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I1b867dec65d458d248706b4118f8d23055eea3a8