Adds host PID mode support for add-ons (#700)

* ✨ Adds host PID mode support for add-ons.

* 🔒 Disables host PID mode when in protected mode

* 🚦 Adds more negative rating weight to host PID mode

hassio/docker/addon.py

@@ -165,6 +165,13 @@ class DockerAddon(DockerInterface):
             return 'host'
         return None
 
+    @property
+    def pid_mode(self):
+        """Return PID mode for addon."""
+        if not self.addon.protected and self.addon.host_pid:
+            return 'host'
+        return None
+
     @property
     def volumes(self):
         """Generate volumes for mappings."""
@@ -277,6 +284,7 @@ class DockerAddon(DockerInterface):
             ipc_mode=self.ipc,
             stdin_open=self.addon.with_stdin,
             network_mode=self.network_mode,
+            pid_mode=self.pid_mode,
             ports=self.ports,
             extra_hosts=self.network_mapping,
             devices=self.devices,