An open-label, multicenter, dose-escalation, phase IA/IB study to evaluate safety, pharmacokinetics, and preliminiary anti-tumor activity of RO7122290, a fibroblast activation protein-? (FAP) targeted 4-1bb ligand (CD137L), with or without obinutuzumab pre-treatment, in patients with advanced and/or metastatic solid tumors as single agent or in combination with atezolizumab followed by tumor specific expansion cohort(s)