Add support for `serenity`

[Giaan37]

Is your device already requested?

• I have searched the existing issues

Brand

xiaomi

Name

redmi A5

Device code

serenity

Model

Redmi 25028RN03A

Device images

https://miuirom.org/phones/redmi-a5

Do you own the device and would be willing to test the installer?

• I own the device and am willing to test the installer on it.

Additional context