Fix on/off button in the Broadlink integration

[felipediel]

The problem

Users are being tricked. Their universal remotes suddenly stop working because we are turning off the button accidentally.

The cause

When the last state is "unavailable" the state is being casted to "off" in async_added_to_hass().

Proposed change

I think we should consider the entity "off" only if the last state is "off". Any other state should be casted to "on". So we don't take the risk of deactivating the remote when the last state is "unavailable".

But now if the user turns the entity off and restarts Home Assistant when the remote is unavailable, the entity will be initialized as "on". Something that seems much less harmful, after all we usually want the entity on. But not perfect yet.

Something I won't touch here, but I leave it as a suggestion: I think that availability should not be mixed with the state. It is difficult to persist the user's choice in this way.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes broadlink remote automatically disabled #42230
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

The integration reached or maintains the following Integration Quality Scale:

• No score or internal
• 🥈 Silver
• 🥇 Gold
• 🏆 Platinum

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[probot-home-assistant]

Hey there @Danielhiversen, mind taking a look at this pull request as its been labeled with an integration (broadlink) you are listed as a codeowner for? Thanks!
_{^{(message by CodeOwnersMention)}}

[elupus]

Hah! That explains how I ended up in that state.

[dgomes]

LGTM

Since it sends UDP packets, could we consider it to be always on ?

[felipediel]

Thaank you! I will add an assumed_state option soon.