[FUI21] Move scrubSubscriberId to utils class

This patch also removes the functionality of returning
original subscriberId in eng build since it is not really useful.

Test: atest NetworkIdentityUtilsTest
Bug: 174123988
Change-Id: I721457e571aa9403a2200b3e4261b4895e4f7a3e
3 files changed
tree: cc01c0070da8d76a0d8ac2a28bc26d7e2f38ddc0
  1. core/
  2. services/