Add flutter 1.5.4-hotfix.2

[lutzroeder]

After making all changes to the cask:

• brew cask audit --download {{cask_file}} is error-free.
• brew cask style --fix {{cask_file}} reports no offenses.
• The commit message includes the cask’s name and version.
• The submission is for a stable version or documented exception.

Additionally, if adding a new cask:

• Named the cask according to the token reference.
• brew cask install {{cask_file}} worked successfully.
• brew cask uninstall {{cask_file}} worked successfully.
• Checked there are no open pull requests for the same cask.
• Checked the cask was not already refused.
• Checked the cask is submitted to the correct repo.

[vitorgalvao]

This seems to be a CLI-only open-source tool. Please submit it first to Homebrew/core as a formula. Return here if not accepted (linking back to the pull request where it was refused).

This policy is documented in faq/rejected_casks:

The app is both open-source and CLI-only (i.e. it only uses the binary artifact). In that case, and in the spirit of deduplication, submit it first to Homebrew/core as a formula that builds from source. If it is rejected, you may then try again as a cask (link us to the issue so we can see the discussion and reasoning for rejection).

[gideongrinberg]

This seems to be a CLI-only open-source tool. Please submit it first to Homebrew/core as a formula. Return here if not accepted (linking back to the pull request where it was refused).

This policy is documented in faq/rejected_casks:

The app is both open-source and CLI-only (i.e. it only uses the binary artifact). In that case, and in the spirit of deduplication, submit it first to Homebrew/core as a formula that builds from source. If it is rejected, you may then try again as a cask (link us to the issue so we can see the discussion and reasoning for rejection).

This was submitted to Homebrew/core, but was rejected as it doesn't build from source. It should be accepted.

[vitorgalvao]

@Gideon357 #78848.