Settings: update About screen device model fields

- Changed "Model name" to "Device model", this queries ro.product.model
- Added an optional "Device name" field which queries ro.product.name
- The new "Device name" field is disabled by default

Change-Id: If837674091b4612124e1eff00e884823be767f47
Signed-off-by: Roman Birg <roman@cyngn.com>