Call ActivateBestChain() on every chainstate.
Declared in <validation.h>
[[locks_excluded(0x7f2e1bc18218), locks_excluded(0x7f2e146b6568), locks_excluded(0x7f2e298fb938), locks_excluded(0x7f2e360b9098)]]
util::Result<void>
ActivateBestChains();
A successful result, or an error if activation failed on any chainstate.