UserLocals: Use computed default for the signed in local

Author: EdricChan03

core/auth/ui/compose/src/main/kotlin/com/edricchan/studybuddy/core/auth/UserLocals.kt

@@ -5,6 +5,7 @@ import androidx.compose.runtime.CompositionLocal
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.ProvidableCompositionLocal
 import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.compositionLocalWithComputedDefaultOf
 import androidx.compose.runtime.getValue
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.google.firebase.Firebase
@@ -18,7 +19,7 @@ val LocalCurrentUser: ProvidableCompositionLocal<FirebaseUser?> =
 
 /** [CompositionLocal] of whether there's a currently signed-in [FirebaseUser]. */
 val LocalIsSignedIn: ProvidableCompositionLocal<Boolean> =
-    compositionLocalOf { Firebase.auth.currentUser != null }
+    compositionLocalWithComputedDefaultOf { LocalCurrentUser.currentValue != null }
 
 /**
  * Provides the [LocalCurrentUser] and [LocalIsSignedIn] composition locals with the