Merge changes from topic "revert-15560568-b194781951-flags-8-ZUNMWRYIZP" into sc-v2-dev

* changes:
  Revert "2/N Rename PluginInstanceManager to PluginActionManager."
  Revert "3/N Remove #getPrivilegedPlugins from PluginInitializer."
  Revert "4/N Remove #handleWtfs from PluginInitializer."
  Revert "5/N Remove PluginInitializer entirely."