Install: Dependency Update does not install downloaded charts

[Illya123]

On install with installoptions.DependencyUpdate=true there is a bug that causes the downloaded dependencies not to be installed.

My troubleshooting in client.go:

• In the func 'install(ctx context.Context, spec *ChartSpec)': The helmChart is loaded before the dependency update, which loads chart.dependencies initially to the locally available charts.
• After downloader.Manager.Update() is called the charts are downloaded, but the dependencies are not updated in the helmChart
• A quick test to reload the helm chart calling c.getChart again solves the problem.