IssueTracker

Component used:
Version used:
```
implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.3.0'
implementation 'androidx.lifecycle:lifecycle-livedata-ktx:2.3.0'
```

Devices/Android versions reproduced on: all

When assigning live data value using `withContext` the lint shows "Expected non-nullable value [NullSafeMutableLiveData]" error.

Sample code:

```
class TestViewModel : ViewModel() {
    private val state = MutableLiveData<Long>()

    // This shows "Expected non-nullable value [NullSafeMutableLiveData]" error.
    fun brokenLoad() {
        viewModelScope.launch {
            state.value = withContext(Dispatchers.Default) { 0L }
        }
    }

    // This works fine.
    fun load() {
        viewModelScope.launch { state.value = giveZero() }
    }

    private suspend fun giveZero() = withContext(Dispatchers.Default) { 0L }
}
```