Prevent displaying AppSettings content until self is non-null.

app/src/main/java/org/thoughtcrime/securesms/components/settings/app/AppSettingsFragment.kt

@@ -92,6 +92,7 @@ class AppSettingsFragment : ComposeFragment(), Callbacks {
     val self by viewModel.self.observeAsState()
 
     if (state == null) return
+    if (self == null) return
 
     val context = LocalContext.current
     val bannerManager = remember {