test: Format predicate source as multiline on error
test: Format predicate source as multiline on error

Github-Pull: #15990
Rebased-From: fa3872e7b4540857261aed948b94b6b2bfdbc3d1

OmniLayer/omnicore,OmniLayer/omnicore,OmniLayer/omnicore,OmniLayer/omnicore,OmniLayer/omnicore,OmniLayer/omnicore