[fenix] Revert "Closes https://github.com/mozilla-mobile/fenix/issues/26750: remove unused files from WallpaperOnboarding"

This reverts commit a81e069440df10a27dd7ea01ac26a5c1b3d7f64f.

app/src/main/java/org/mozilla/fenix/wallpapers/WallpaperOnboarding.kt

@@ -23,9 +23,11 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
 import org.mozilla.fenix.R
 import org.mozilla.fenix.settings.wallpaper.WallpaperThumbnails
 import org.mozilla.fenix.theme.FirefoxTheme