Pull SecureBox.java out into its own library.

SecureBox is needed by Settings for encrypting device credential and
was inaccessible from services/core/java/com/android/server.
Create a new SecureBox library to resolve.

Test: atest com.android.server.locksettings.recoverablekeystore
SecureBoxTests
Bug: 258505917

Change-Id: I65484edf12b04dfe1642cd0c97bc999d26430395
16 files changed