Abseil's string_view fallback handling question

[AbrilRBS]

Hi!

In Conan Center Index we got a report indicating that Abseil was being picked up, which was unexpected as no find_package for abseil is performed, so a system installed one was being picked up instead of a Conan-provided one, which caused compilation errors for the user. (It's only find_package'ed as part of FLATBUFFERS_BUILD_GRPCTEST, which as far as I can see, it's a distinct path from the above issue, but please correct me if I'm mistaken!)

So we wanted to know if there is a way/plans for a way to completely disable this fallback? (And/or make the Abseil dependency explicit when needed)

PS: In #7897 a check for ABSL_USES_STD_STRING_VIEW was added to avoid some of the compilation errors that this fallback might cause, but as far as I can see, that'd still fail on the OP's case

Thanks! :)