homeassistant-config-blueprint-dashboard: Configuration improvements

* Use HOMEASSISTANT_TRUSTED_NETWORK (defaults to 192.168.0.0/24)
  variable to define trusted networks in the HomeAssisstant
  configuration.
* Default configuration to autologin when client from
  HOMEASSISTANT_TRUSTED_NETWORK and only one user is available (better
  experience with touchscreen modules).
* Predefine automations setup to include LED control based on human
  presence sensor.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>