fix(workflows): run apt-get update before install

[Coronon]

Description

The Linux build tests always failed because the apt-get install command errored.
This PR runs apt-get update before any install.

Examples:

• Failing test
• Successful test

Related Issues

No issue yet

Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I titled the PR using Conventional Commits.
• I did not modify the CHANGELOG.md nor the pubspec.yaml files.
• All existing and new tests are passing.
• The analyzer (flutter analyze) does not report any problems on my PR.

Breaking Change

Does your PR require plugin users to manually update their apps to accommodate your change?

• Yes, this is a breaking change (please indicate that with a ! in the title as explained in Conventional Commits).
• No, this is not a breaking change.

[miquelbeltran]

LGTM. Re-running the Android integration tests, just in case. Although the changes are unrelated.

[vbuberen]

Looks good to me. Thanks for your contribution.

As to failing Android 21 test - it was there before and I will look at it soon.