Restart on resume

[lostintangent]

This extends/replaces the previous restartImmediately flag by allowing the caller to pass a restartMode to LocalPackage.apply, which adds the ability to restart the app on the next resume, as opposed to simply restarting immediately or not. The default value when a mode isn't specified is still "immediate", but this change gives devs more options, particularly if they want to employ a "silent update" mechanism, which doesn't immediately restart the app, but does on the next app resume.

Moving forward, we could also expose an API to script that allows restarting the app at a custom, app-specific time, that way you apply the update, specifying a restart mode of none, and then force the restart sooner at a point the app can determine is acceptable (e.g. the end-user navigated back to the home page).

This change only impacts the LocalPackage.apply method. We need to determine how to best expose the restartMode via sync, in a way that still respects the isMandatory option of an update and doesn't allow the app to have a weird update experience (e.g. not applying the update immediately is kind of strange when you asked the end-user for permission to install it). We'll address that in a future PR, along with exposing the new progressCallback feature that was added to the RemotePackage.download method.

[geof90]

Any way to const-tize the keys "rollbackTimeout" and "allowRestartOnResume"?

[lostintangent]

Good idea. I'm const-ify those two and the "hash" key while I'm at it.

[geof90]

LGTM, it is a great feature to have.

[dtivel]

unnecessarily

[dtivel]

Looks good.