About Android FBE information is as follows：
https://source.android.com/security/encryption/file-based
https://developer.android.com/training/articles/direct-boot

My app starts by receiving "android.intent.action.LOCKED_BOOT_COMPLETED", WorkManager initial before user unlocked.

It cause crash:
java.lang.IllegalStateException: SharedPreferences in credential encrypted storage are not available until after user is unlocked

Because WorkManager use context.applicationContext accessing data/data/package/xxxx.

I tried to disable WorkManagerInitializer in AndroidManifest.xml and initial WorkManager on my first activity.But it cause another crash:
08-16 11:02:07.441 E/AndroidRuntime(19740): java.lang.RuntimeException: Unable to create service androidx.work.impl.background.systemjob.SystemJobService: java.lang.IllegalStateException: WorkManager needs to be initialized via a ContentProvider#onCreate() or an Application#onCreate().
08-16 11:02:07.441 E/AndroidRuntime(19740): at android.app.ActivityThread.handleCreateService(ActivityThread.java:3415)
08-16 11:02:07.441 E/AndroidRuntime(19740): at android.app.ActivityThread.-wrap4(Unknown Source:0)
08-16 11:02:07.441 E/AndroidRuntime(19740): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1738)
08-16 11:02:07.441 E/AndroidRuntime(19740): at android.os.Handler.dispatchMessage(Handler.java:106)
08-16 11:02:07.441 E/AndroidRuntime(19740): at android.os.Looper.loop(Looper.java:164)
08-16 11:02:07.441 E/AndroidRuntime(19740): at android.app.ActivityThread.main(ActivityThread.java:6618)
08-16 11:02:07.441 E/AndroidRuntime(19740): at java.lang.reflect.Method.invoke(Native Method)
08-16 11:02:07.441 E/AndroidRuntime(19740): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
08-16 11:02:07.441 E/AndroidRuntime(19740): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:810)
08-16 11:02:07.441 E/AndroidRuntime(19740): Caused by: java.lang.IllegalStateException: WorkManager needs to be initialized via a ContentProvider#onCreate() or an Application#onCreate().
08-16 11:02:07.441 E/AndroidRuntime(19740): at androidx.work.impl.background.systemjob.SystemJobService.onCreate(SystemJobService.java:67)
08-16 11:02:07.441 E/AndroidRuntime(19740): at android.app.ActivityThread.handleCreateService(ActivityThread.java:3405)
08-16 11:02:07.441 E/AndroidRuntime(19740): ... 8 more