Prevent blank sim label showing on screen.

fix: 333642116
Test: Manual test, see b/333642116#14
Change-Id: I776135d8ba609c4ea1fac47cfb765e00f8525497

src/com/android/settings/spa/network/SimOnboardingLabelSim.kt

@@ -111,7 +111,7 @@ private fun LabelSimPreference(
                 placeholder = {Text(text = originalSimCarrierName)},
                 modifier = Modifier.fillMaxWidth()
             ) {
-                titleSimName = it
+                titleSimName = if (it.isEmpty()) originalSimCarrierName else it
             }
         },
     )