Add immersive experience in focus mode of InAppGallery

Author: MHShetty

app/src/main/java/app/grapheneos/camera/ui/composable/screen/ui/GalleryScreen.kt

@@ -27,6 +27,7 @@ import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.Text
 
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 
@@ -144,6 +145,12 @@ fun GalleryScreen(
         }
     }
 
+    DisposableEffect(Unit) {
+        onDispose {
+            insetsController.show(WindowInsetsCompat.Type.systemBars())
+        }
+    }
+
     // Displays media info dialog when displayedMediaItem is not null
     MediaInfoDialog(
         mediaItemDetails = viewModel.displayedMediaItem,