Initial rebrand of tree to support POCO X3 (karna) / POCO X3 NFC (surya)
* Import device specifics in README.md
* Rebrand targets
* Set correct name in base files
* Modify custom init to set proper variants

Surya comes in two flavors: surya and karna (surya india)
Hardware is almost identical, except for battery size and
missing NFC on Karna

Surya was launched with Android 10, API level 29

Change-Id: I1ef0e5e7a358bb6e4e61406fe4d5d2255349acb3