Don't crash if default supervision profile owner is not set

Bug: 175430552
Bug: 197399948
Test: build, flash, watch logcat

Change-Id: If441946fa278c04ae88122f6243f5a7dedd96ebc
Merged-In: If441946fa278c04ae88122f6243f5a7dedd96ebc
(cherry picked from commit bd27c365915f824824d865668c63a2119c4700fb)
(cherry picked from commit bcb5ee6f43ea24fb74649f164ca3c3032a7be3b5)
1 file changed