[automerge] [DO NOT MERGE] passpoint: validate decorated identity prefix 2p: 68abe8f273

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Wifi/+/20035262

Bug: 246539931
Change-Id: Ibeda4953105ed8c7843fb7dee3408cbb16401c54