Merge "Remove the duplicated RFC7421_PREFIX_LENGTH constants." into main am: 6c8fb01159

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2707195

Change-Id: I6467c027b16b616a0c1362f0a1a3e8ddfa20b305
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>