You can't fsync(2) /dev/urandom...

...so don't even try. Doing so leads to this:

W/EntropyService( 1586): unable to load initial entropy (first boot?)
W/EntropyService( 1586): java.io.SyncFailedException: fsync failed: EINVAL (Invalid argument)
W/EntropyService( 1586): 	at java.io.FileDescriptor.sync(FileDescriptor.java:73)
W/EntropyService( 1586): 	at java.io.RandomAccessFile.write(RandomAccessFile.java:694)
W/EntropyService( 1586): 	at java.io.RandomAccessFile.write(RandomAccessFile.java:676)
W/EntropyService( 1586): 	at com.android.server.RandomBlock.toDataOut(RandomBlock.java:88)
W/EntropyService( 1586): 	at com.android.server.RandomBlock.toFile(RandomBlock.java:70)
W/EntropyService( 1586): 	at com.android.server.EntropyService.loadInitialEntropy(EntropyService.java:99)
W/EntropyService( 1586): 	at com.android.server.EntropyService.<init>(EntropyService.java:86)
W/EntropyService( 1586): 	at com.android.server.EntropyService.<init>(EntropyService.java:76)
W/EntropyService( 1586): 	at com.android.server.ServerThread.run(SystemServer.java:139)
W/EntropyService( 1586): Caused by: libcore.io.ErrnoException: fsync failed: EINVAL (Invalid argument)
W/EntropyService( 1586): 	at libcore.io.Posix.fsync(Native Method)
W/EntropyService( 1586): 	at libcore.io.BlockGuardOs.fsync(BlockGuardOs.java:39)
W/EntropyService( 1586): 	at java.io.FileDescriptor.sync(FileDescriptor.java:71)
W/EntropyService( 1586): 	... 8 more

Change-Id: I598a9456eccec0ca087f1568d47b6b8e531de8a8