Add old DeviceInfo version documentation

Since comments are stripped from the stable AIDL snapshots, the CDDL
describing the DeviceInfo contents is lost for the older versions. Add
the comments from older DeviceInfo versions as a reference for
maintainers of older HAL implementations.

Test: n/a
Change-Id: I7dd3d285b3d8422a6df4228ad0cf5797e78609c1