Fix: TransactionTooLargeException crash

[0nko]

Task/Issue URL: https://app.asana.com/1/137249556945/project/1202552961248957/task/1210238988495963?focus=true

Description

This PR saves the TabPagerAdapter to disk instead of the state instance Bundle, which should potentially prevent any/most TransactionTooLargeException crashes when the saveStateToDataStore feature flag is enabled.

Although the tab swiping feature reduces the limit of active tabs from 40 to 20, which should prevent the original crash, the ViewPager2 adapter needs to save its state, which again increases the amount of data saved and causes the crash.

Steps to test this PR

• Generate 100 tabs in DDG developer settings
• Enable Don't keep activities in the device Developer options
• Swipe between tabs (~40 times)
• Switch to a different app
• Reopen DDG
• Notice the app doesn't crash

---

• To see the specific tasks where the Asana app for GitHub is being used, see below:
  • https://app.asana.com/0/0/1208271988740971

[cmonfortep]

why do we have a runblocking here? this will block main thread and cause ANRs

[0nko]

The TabsDataStore.saveState() function is suspended so I was worried that when the activity is finishing and onSaveInstanceState() would launch a coroutine and then continue, the app might get killed before it can finish saving data. Previously, the state was also getting saved synchronously. But maybe I'm wrong..

[0nko]

AI agrees :)

Launching a coroutine in onSaveInstanceState() is not safe

onSaveInstanceState() is called when an Activity might be destroyed, and the Android system expects you to quickly save minimal state data synchronously in this method. The Bundle you provide must be completely populated by the time the method returns.

Problems with launching a coroutine in onSaveInstanceState():

• Coroutines run asynchronously, so any state saved after the method returns won't make it into the Bundle
• The Activity might be destroyed before the coroutine completes
• The lifecycle of the coroutine wouldn't be properly managed

Instead, you should:

• Save state synchronously in onSaveInstanceState()
• Do any heavy operations earlier in the Activity lifecycle
• Use ViewModel with SavedStateHandle for more complex state saving
• If you need to save state that requires async operations, it's better to do that proactively during normal Activity operation, not during the saving process.

[cmonfortep]

Just flagging this is danger territory and maybe the approach is not correct. The activity is being destroyed but you are blocking the UI thread until operation finishes and that will produce an ANR.

I see you want to persist the ViewState, and it's suspend because you rely on DataStore. But is dataStore the place where to store that state? do you need to persist into disk? do you want to recover from app being killed?