Fix null pointer in SubscriptionUtil

Sometimes we get null sub info which causes a crash. This just
makes it so that if we see that we treat it as inactive since
there isn't really a world where an active null sub info makes
sense.

Test: atest SubscriptionUtilTest
Bug: 131603073
Change-Id: Id5ecbecf011e19ff02d9465e0571b1d17c83de9a

src/com/android/settings/network/SubscriptionUtil.java

@@ -59,7 +59,11 @@ public class SubscriptionUtil {
         return subscriptions;
     }
 
-    private static boolean isInactiveInsertedPSim(UiccSlotInfo slotInfo) {
+    @VisibleForTesting
+    static boolean isInactiveInsertedPSim(UiccSlotInfo slotInfo) {
+        if (slotInfo == null)  {
+            return false;
+        }
         return !slotInfo.getIsEuicc() && !slotInfo.getIsActive() &&
                 slotInfo.getCardStateInfo() == CARD_STATE_INFO_PRESENT;
     }