base

Duplicate file descriptor when dumping asynchronously.

dumpDbInfo() uses an async task when dumping from the system thread, but
then the file descriptor is closed by the time the task is executed. As
such, the system databases are not dumped.

BUG: 29123428
Change-Id: Ibb8bbe503aa03c3ca13b2b1789f0ead0b869e9d5