The bash history is an unintended form of documentation and also a way
to see what happened but by default it doesn't tell you when.
Before this change:
$ history
1 uname -a
2 sudo reboot
After this change:
$ history
1 2017-12-20T23:50:28+0000 uname -a
2 2017-12-20T23:50:35+0000 sudo reboot
Note that any entries in the bash history before this change will be
defaulted to when the change takes place.
Change-Id: I4443f00ab050891a16e545315ee88ae24893ac5d