Use oo_spawn for all root scoped shell commands

Revert previous changes which replaced oo_spawn calls with ApplicationContainer.run_in_root_context.

The oo_spawn method was intentionally designed to be the single execution path for all shell executions,
for security and clarity. Adding a second execution path to oo_spawn not only results in multiple ways
to do the same thing, but having such a method in ApplicationContainer specifically promotes creating
unwarranted/undesirable dependencies on ApplicationContainer where no dependency was previously
necessary.