Use google groups for CCs in OSS-Fuzz issue tracker

[ViniciustCosta]

This PR is related to the oss-fuzz issue tracker logic in clusterfuzz. It switches from CCing individual users from oss-fuzz projects to CCing the correspondent project CC google group.

This should be merged and deployed after:

• Confirming that the cc groups are working as expected (containing all the correct members);
• Backfilled all current open issues with the project group;
• Disabled apply_ccs cronjob;
• PR in clusterfuzz-config adding the project.yaml value for issue_cc_groups customer_id and domain.
• Backfilled all oss-fuzz users' PermissionEntityKind in datastore to the new auto_cc type -> this will need to be done in the same PR as it depends on changes here;

Context: b/477964128