Kotlin 1.9.0 (#3835)

Update to Kotlin 1.9.0 and migrate to newer language idioms.

- Remove unnecessary @OptIn for features migrated to mainstream
- Use `data object` where appropriate
- Use new enum `entries` property

app/src/main/java/com/keylesspalace/tusky/components/compose/ComposeViewModel.kt

@@ -39,7 +39,6 @@ import com.keylesspalace.tusky.service.ServiceClient
 import com.keylesspalace.tusky.service.StatusToSend
 import com.keylesspalace.tusky.util.randomAlphanumericString
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.FlowPreview
 import kotlinx.coroutines.channels.BufferOverflow
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -53,7 +52,6 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import javax.inject.Inject
 
-@OptIn(FlowPreview::class)
 class ComposeViewModel @Inject constructor(
     private val api: MastodonApi,
     private val accountManager: AccountManager,
@@ -95,7 +93,7 @@ class ComposeViewModel @Inject constructor(
     val media: MutableStateFlow<List<QueuedMedia>> = MutableStateFlow(emptyList())
     val uploadError = MutableSharedFlow<Throwable>(replay = 0, extraBufferCapacity = 1, onBufferOverflow = BufferOverflow.DROP_OLDEST)
 
-    lateinit var composeKind: ComposeKind
+    private lateinit var composeKind: ComposeKind
 
     // Used in ComposeActivity to pass state to result function when cropImage contract inflight
     var cropImageItemOld: QueuedMedia? = null

app/src/main/java/com/keylesspalace/tusky/components/compose/dialog/AddPollOptionsAdapter.kt

@@ -75,10 +75,6 @@ class AddPollOptionsAdapter(
     }
 
     private fun validateInput(): Boolean {
-        if (options.contains("") || options.distinct().size != options.size) {
-            return false
-        }
-
-        return true
+        return !(options.contains("") || options.distinct().size != options.size)
     }
 }