Merge "Remove the duplicated RFC7421_PREFIX_LENGTH constants." into main am: 6c8fb01159 am: b8a745503d am: 9c1d1d5bc4

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

Change-Id: I2ccf09733f5cc10359bb7ddeda835230eb07ce18
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>