message: docs(service-worker): add info about recovering from degraded Driver state
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diff: @@ -207,6 +207,9 @@ There are two possible degraded states:
  clean copy of the latest known version of the app. Older cached
  versions are safe to use, so existing tabs continue to run from
  cache, but new loads of the app will be served from the network.
  +The service worker will try to recover from this state when a new
  +version of the application is detected and installed (that is,
  +when a new `ngsw.json` is available).
  * `SAFE_MODE`: the service worker cannot guarantee the safety of
  using cached data. Either an unexpected error occurred or all
  @@ -216,6 +219,12 @@ network, running as little service worker code as possible.
  In both cases, the parenthetical annotation provides the
  error that caused the service worker to enter the degraded state.
  +Both states are temporary; they are saved only for the lifetime of the [ServiceWorker
  +instance](https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorkerGlobalScope).
  +The browser sometimes terminates an idle service worker to conserve memory and
  +processor power, and creates a new service worker instance in response to
  +network events. The new instance starts in the `NORMAL` mode, regardless of the
  +state of the previous instance.
  #### Latest manifest hash
  