Cleanup core_main() in package.py
Cleanup core_main() in package.py

General cleanup and fix of b/242184878

Change-Id: Ia53f5837fe0f8b6925140e8685a2239721aafbb0
GitOrigin-RevId: a9bbf24cfcada173eb6cf2c6adcc3ccfb1419095

google-coral/coralmicro,google-coral/coralmicro,google-coral/coralmicro,google-coral/coralmicro,google-coral/coralmicro