This reverts commit 42de44592f. It appears
there might be thread-safety issues as panics have started occuring when
parallism is ramped up. Reverting for now while investigating.
* Fix bug where scheduling.automatic_restart false is never used
* Remove deprecated automatic_restart value in favor of scheduling.automatic_restart
* Remove deprecated on_host_maintenance
* Correct bad var name
* Re-add removed schema values and marked as Removed
* Fix var to snake case
* Migrate empty scheduling blocks in compute_instance_template
* Shorten error message
* Use only one return value instead of two