Composite GitHub Actions to setup and cache the Flutter SDK.

This action is intended for the Hosted Runners.
It does the following:

• Checks the SHA of the requested input ref (defaults to stable) from the GitHub flutter repo and stores in $FLUTTER_REF_HEAD.
• Checks for the cache entry with key flutter-${{ runner.os }}-${{ inputs.ref }}-${{ env.FLUTTER_REF_HEAD }}.
• If the cache hit is true then it restores in the $RUNNER_TOOL_CACHE/flutter folder.
• If the cache hit is false then it downloads the Flutter from the GitHub repo to $RUNNER_TOOL_CACHE/flutter folder.
• Adds $RUNNER_TOOL_CACHE/flutter/bin folder to the $GITHUB_PATH.
• Runs flutter --version.
• If the cache hit was false then post job success, it caches $RUNNER_TOOL_CACHE/flutter folder using the key flutter-${{ runner.os }}-${{ inputs.ref }}-${{ env.FLUTTER_REF_HEAD }}.

Note that GitHub will remove any cache entries that have not been accessed in over 7 days.
This will help to save some minutes. Which matters if your repository is private.

Basic -

steps:
  - uses: actions/checkout@v2
  - name: Setup Flutter
    uses: hrishikesh-kadam/setup-flutter@v1
  - run: # Run your flutter or dart command here

With specific reference -

steps:
  - uses: actions/checkout@v2
  - name: Setup Flutter
    uses: hrishikesh-kadam/setup-flutter@v1
    with:
      ref: beta # or 2.8 or 2.8.0-3.3.pre,
  - run: # Run your flutter or dart command here