ONG amount precision and symbol on device display incorrect

When signing a transaction on the device, the asset symbol and amount shown for the transaction details for ONG is incorrect.

Steps to reproduce:
- Send a serialized transfer transaction
    - Test amount 0.05 ONG
- Navigate to view the transaction details on the device

Expected:
- Display should show `ONG 0.05`

Actual:
- Display shows `ONT 50000000`