Pref tree handler cannot assume preference has non-null key. Change-Id: I790e75f3b4c888e2a48b297bea89cda0b8dbaabd Fix: 35855587 Test: runtest --path tests/app/src/com/android/settings/EncryptionInterstitialTest.java
Bug: 24405946 Change-Id: I1fed96cbc228b6bb367637f83f9cd3bac2761417
bug:27206957 Change-Id: Ib577440a2696539f44021bb4ba0100e9f1699c6c