Add mIccFdnAvailable to UiccCardapplication toString.

Although the logs for onQueryFdnEnabled will show this, it is entirely
possible that the query happened earlier in the logcat and rolled over.
Hence adding this to the toString to ensure the dumpsys conveys the full
picture.

Test: Manual test to see dumpsys
Flag: NONE logs only change.
Bug: 427790201
Change-Id: I1a711a3983a4649934ae05b57619e828d6094603