hotspot2: update Passpoint intent definitions

Address API Councils comment on the newly added intent definitions
for Passpoint events:
- Use a Parcelable class to represent icon info
- Document all extras that are included for an action
- Document that the new intents will only be sent to registered
  receivers, and not manifest receivers
- Rename extras to be more generic

While there, removed the deprecated hidden Passpoint intent
definitions.

Bug: 35857805
Test: frameworks/base/wifi/tests/runtests.sh
Change-Id: I22de2d52fce3ed1adc8d72bf1580d3337bc747c5
Merged-In: I22de2d52fce3ed1adc8d72bf1580d3337bc747c5