DB Wipe detection

- Create a check file for each database in order to detect
1) an unexpected DB file removal
2) DB wipe caused by a DB corruption.

- Either case, do a WTF to collect information on APR.

- Also print file timestamps in "dumpsys dbinfo". Example:

=====================
Database files in /data/system:
  locksettings.db                            20480b ctime=2018-10-23T22:48:35Z mtime=2018-10-23T22:48:35Z atime=2018-10-23T18:54:12Z
  locksettings.db-wipecheck                      0b ctime=2018-10-23T18:54:12Z mtime=2018-10-23T18:54:12Z atime=2018-10-23T18:54:12Z
  notification_log.db                        45056b ctime=2018-10-23T22:48:08Z mtime=2018-10-23T22:48:08Z atime=2018-10-23T18:54:13Z
    :
=====================

Change-Id: I77fbeb0bb635c787aba797412f116475fecbe41c
Fixes: 117886381
Test: manual test

Test 1: corruption
1. Stop CP2 process (adb shell killall android.process.acore)
2. shell 'echo abc > /data/user/0/com.android.providers.contacts/databases/contacts2.db'
3. Launch the contacts app.

Test 2: Unexpected file removal
1. Stop CP2 process (adb shell killall android.process.acore)
2. shell 'rm -f /data/user/0/com.android.providers.contacts/databases/contacts2.db'
3. Launch the contacts app.

In both cases, logcat shows a client side stacktrace and also a WTF. (am_wtf)