Don't call update() in Entity constructor

[bachya]

Description:

Per developer guidelines, making appropriate adjustment.

Related issue (if applicable): N/A

Pull request in home-assistant.github.io with documentation (if applicable): N/A

Example entry for configuration.yaml (if applicable):

sensor:
  - platform: command_line
    name: Test
    command: 'echo $RANDOM'

Checklist:

If the code does not interact with devices:

• Local tests with tox run successfully. Your PR cannot be merged unless tests pass
• Tests have been added to verify that the new code works.

[mention-bot]

@bachya, thanks for your PR! By analyzing the history of the files in this pull request, we identified @devdelay, @fabaff and @philipbl to be potential reviewers.

[bachya]

Duplicate of #8892; closing.