[Telephony] Clean up: remove getApnTypeStringInternal

Bug: 181696914
Test: make
Change-Id: Ia79bb9eaa1fc43a2995730da47289274f94d67fe

telephony/java/android/telephony/data/ApnSetting.java

@@ -1567,16 +1567,6 @@ public class ApnSetting implements Parcelable {
         return apnTypeString == null ? "" : apnTypeString;
     }
 
-    /**
-     * Same as {@link #getApnTypeString(int)}, but returns "Unknown" instead of an empty string
-     * when provided with an invalid int for compatibility purposes.
-     * @hide
-     */
-    public static @NonNull String getApnTypeStringInternal(@ApnType int apnType) {
-        String result = getApnTypeString(apnType);
-        return TextUtils.isEmpty(result) ? "Unknown" : result;
-    }
-
     /**
      * Converts the string representation of an APN type to its integer representation.
      *