AMessage::FromParcel(): Limit recursion depth; report NULL on failure.

- FromParcel() now takes as an optional parameter the maximum recursion depth.
  (The default value is currently set to 255.) On the event that the input
  parcel has AMessage nested deeper than the maximum recursion depth,
  FromParcel() will return NULL.
- Also, when the input parcel has items that are not recognized by FromParcel(),
  NULL will be returned. (The old behavior was to invoke TRESPASS, which would
  cause the process to stop.)

Bug: 28332724
Change-Id: I722097f7d1711668f197651d7e8135d703f6c91f