When logging with color, it is necessary to reset the color at the
end of each line to avoid the color bleeding into subsequent log
lines. This change adds a new key to the record called 'reset_color'
that serves as a shortcut to the escape sequence to reset the color.
It also provides documentation for the ColorHandler class that
explains how to use it.
Change-Id: I68f1c716cbed241f79fa65dae1affe810b8e6e30
Closes-Bug: 1731477