Limit the size of lists in ZenPolicy

These lists are already size-limited by the set of things they may depict, but this change enforces the list sizes upon reading from a parcel in case any callers change the list sizes via reflection or something like it.

Bug: 251427644
Test: atest ZenPolicyTest
Change-Id: I301ee58afa03b6695294e8a46280169ecbbd3ba1