With REST only clients map fields are having trouble parsing the correct resourceType

For reference: https://github.com/googleapis/gapic-generator-php/pull/540#discussion_r1038564185

This primarily came up with the compute paginated snippets. When grabbing the resourceType it was coming back as a class of "ItemsEntry", despite the protos indicating something else. We should research why this is happening and solve for it so we can re-enable the inline var block.