Disallow PAP authentication when MPPE is requested am: 4f319df8ff am: 49f031ea4d am: 2f74509789 am: c14e995495

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17614780

Change-Id: Ifb8d0d20243e35601011eedb9442594f24067fe0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>