What's the purpose of .properties files in APK packages?

When analyzing an APK, I've found a whole lot of .properties files in the archive's root, indicating the version numbers of Google Play services, Firebase and the Google HTTP client, for example:

version=19.2.0
client=firebase-database
firebase-database_client=19.2.0

These could theoretically be excluded from the package alike:

android {
    packagingOptions {
        exclude "firebase-*.properties"
        exclude "play-services-*.properties"
        exclude "google-http-client.version"
    }
}

However, this issue suggests it would be the "intended behavior". So is it safe to exclude these seemingly useless files from the package - or are they required by Google Play, in order to expose these version numbers to automated package-content scans? Is the purpose of these version number files documented somewhere?

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Here's a screenshot of what I'm talking about:

from What's the purpose of .properties files in APK packages?