Merge "Throw IllegalStateException when inserting an existing item" into main am: e7d67662a9 am: 7bf26f7404

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3254276

Change-Id: Ie77bd00daf7ee14e339d9246947c9092b8ff70be
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>