Fixed "Unlock your phone" unexpectedlly turned ON after OTA

If the new setting key is not set, we should use the value of the old
ones as the default value.

Bug: 444673089
Test: atest BiometricServiceTest
Flag: EXEMPT BUGFIX
(cherry picked from commit a3799e443e9fdbbcbc96824b8d2fc1e4c683bb7e)
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:2b8bc2b15f2aceb4e2a379209997afce16427e76
Merged-In: I902c7fd9781037ba05b30821b4fa22aa1509f3fd
Change-Id: I902c7fd9781037ba05b30821b4fa22aa1509f3fd
2 files changed