This will make it harder to inadvertently register new field trials in
the wrong collection. This has happened before, see 88a8e44a51 ("Remove
nonexempt field trials from POLICY_EXEMPT_FIELD_TRIALS") for example.
Additionally, field trials will now also be validated by default before
a C++ header is generated.
Bug: None
Change-Id: I298c1345d48a522ecb95fd0f0e09834c8bdff40a
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/346543
Reviewed-by: Jeremy Leconte <jleconte@google.com>
Commit-Queue: Emil Lundmark <lndmrk@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42034}
f505c7be44