StrictMode: Preferences Storage SQLite StrictModeDiskReadViolation

It seems that DiskIO should be done on another Thread.

In case this was not a known-and-ignored warning, here the Stacktrace:

10-23 19:20:02.287 30354 30354 D StrictMode: StrictMode policy violation; ~duration=71 ms: android.os.StrictMode$StrictModeDiskReadViolation: policy=31 violation=2
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.os.StrictMode$AndroidBlockGuardPolicy.onReadFromDisk(StrictMode.java:1137)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteConnection.applyBlockGuardPolicy(SQLiteConnection.java:1043)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteConnection.executeForLong(SQLiteConnection.java:597)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteConnection.setPageSize(SQLiteConnection.java:251)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:213)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:806)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:791)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:1179)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:1168)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:268)
10-23 19:20:02.287 30354 30354 D StrictMode:    at com.fsck.k9.preferences.Storage.openDB(Storage.java:44)
10-23 19:20:02.287 30354 30354 D StrictMode:    at com.fsck.k9.preferences.Storage.loadValues(Storage.java:177)
10-23 19:20:02.287 30354 30354 D StrictMode:    at com.fsck.k9.preferences.Storage.<init>(Storage.java:200)
10-23 19:20:02.287 30354 30354 D StrictMode:    at com.fsck.k9.preferences.Storage.getStorage(Storage.java:155)
10-23 19:20:02.287 30354 30354 D StrictMode:    at com.fsck.k9.Preferences.<init>(Preferences.java:44)
10-23 19:20:02.287 30354 30354 D StrictMode:    at com.fsck.k9.Preferences.getPreferences(Preferences.java:31)
10-23 19:20:02.287 30354 30354 D StrictMode:    at com.fsck.k9.K9.onCreate(K9.java:583)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1012)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4593)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.app.ActivityThread.access$1600(ActivityThread.java:154)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1382)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.os.Handler.dispatchMessage(Handler.java:102)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.os.Looper.loop(Looper.java:135)
10-23 19:20:02.287 30354 30354 D StrictMode:    at android.app.ActivityThread.main(ActivityThread.java:5294)
10-23 19:20:02.287 30354 30354 D StrictMode:    at java.lang.reflect.Method.invoke(Native Method)
10-23 19:20:02.287 30354 30354 D StrictMode:    at java.lang.reflect.Method.invoke(Method.java:372)
10-23 19:20:02.287 30354 30354 D StrictMode:    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
10-23 19:20:02.287 30354 30354 D StrictMode:    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)

Start by reading Storage.java, especially openDB(), loadValues(), and initialization, then trace how Preferences.java and K9.onCreate() access storage. Verify the reported StrictModeDiskReadViolation and determine how the preferences database access should avoid the application main thread, with tests or startup behavior showing that the warning is resolved.