[android_alarm_manager] Fix pod lint warnings

[jmagman]

Description

Fix android_alarm_manager pod lib lint warnings:

 -> android_alarm_manager (0.0.1)
    - WARN  | license: Missing license type.
    - WARN  | description: The description is equal to the summary.
    - WARN  | [iOS] keys: Missing primary key for `source` attribute. The acceptable ones are: `git, hg, http, svn`.
...
[!] android_alarm_manager did not pass validation, due to 3 warnings (but you can use `--allow-warnings` to ignore them).

Related Issues

flutter/flutter#55245
Dependency to merge https://github.com/flutter/plugin_tools/pull/97

Checklist

Before you create this PR confirm that it meets all requirements listed below by checking the relevant checkboxes ([x]). This will ensure a smooth and quick review process.

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See [Contributor Guide]).
• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
• The analyzer (flutter analyze) does not report any problems on my PR.
• I read and followed the [Flutter Style Guide].
• The title of the PR starts with the name of the plugin surrounded by square brackets, e.g. [shared_preferences]
• I updated pubspec.yaml with an appropriate new version according to the [pub versioning philosophy].
• I updated CHANGELOG.md to add a description of the change.
• I signed the [CLA].
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

• Yes, this is a breaking change (please indicate a breaking change in CHANGELOG.md and increment major revision).
• No, this is not a breaking change.

[jmagman]

This is a bogus source since there's nothing to download at this URL and downloading is handled by pub, not CocoaPods tooling.

[jmagman]

Open to suggestions for this wording. It's not displayed anywhere.