Merge "Document emergency case for setAllowedNetworkTypeBitmap" am: e9fb347e0b am: fd6c4f5f5d am: e8615e0ec7

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1531900

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ia82a1a8b33422c9ffb413947cb41a3a68f8261d2