Fix UiccSlotInfo.getCardId for inactive eUICC

This was incorrectly returning the ICCID. Now we will return null.

Test: manual and atest TelephonyManagerTest#testGetUiccSlotsInfo
Bug: 131423779
Change-Id: I8cb4ce7779884d6b9b21aa378e9794fb20d230d9
(cherry picked from commit cdb04cd4184c39df067c8524c579e727fbf159ce)
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 18911ef..df589fd 100755
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -6365,11 +6365,11 @@
                     continue;
                 }
 
-                String cardId;
+                String cardId = null;
                 UiccCard card = slot.getUiccCard();
                 if (card != null) {
                     cardId = card.getCardId();
-                } else {
+                } else if (!slot.isEuicc()) {
                     cardId = slot.getIccId();
                 }