fix(core): merge per-call restOptions with the client-level ones - #9437

fix(core): merge per-call restOptions with the client-level ones#9437

smichaelsen wants to merge 2 commits into

googleapis:maingoogleapis/google-cloud-php:mainfrom

smichaelsen:fix-core-request-options-mergesmichaelsen/google-cloud-php:fix-core-request-options-mergeCopy head branch name to clipboard