Rename FusedAPIInterface in ApplicationInstaller

Description

FusedAPIInterface has been renamed in ApplicationInstaller.

ApplicationInstaller has also been sanitized:

interface ApplicationInstaller {

    fun installApplication(app: FusedApp)

    fun cancelDownload(app: FusedApp)
}

Previous parameters appIcon: ImageView? of installApplication() was never used.

Screenshots

Technical details

Tests

Issues

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