Explicitly mention a confusing proto3 infelicity.

// NOTE TO OEMS:

// If you add custom fields to this proto, do not use numbers in the reserved range.

// NOTE TO CONSUMERS:

// With proto3 -- unlike proto2 -- HasValue is unreliable for any field

// where the default value for that type is also a valid value for the field.

// This means, for example, that a boolean that is false or an integer that

// is zero will appear to be missing --- but because they're not actually

// marked as `optional` in this schema, consumers should just use values

// without first checking whether or not they're "present".

// https://protobuf.dev/programming-guides/proto3/#default

message CrashDetail {

  bytes name = 1;

  bytes data = 2;