you Downloaded firmware for Huawei Y6 Prime (2018) Atomu-L21 with build Huawei Y6 Prime 2018 ( Honor 7A ) ATU-L21 hw eu HLRCF Atomu-L21 8.0.0.154(C738CUSTC738D1) Firmware 8.0.0 r1 EMUI8.0 05015ELH
Huawei Y6 Prime (2018) Atomu-L21 Published on Released 2018, May . with Android 8.0; EMUI 8.
Display size on Huawei Y6 Prime (2018) is 5.7" and the resolution is 720x1440 pixels

You can flash The Stock firmware of Atomu-L21 using This Guide.
more about Huawei Y6 Prime 2018 Atomu-L21:

this model of huawei powerd by Quad-core 1.4 GHz Cortex-A53 and the internal storage size and ram size is 32GB storage, microSD card slot.
also it can support microSD, up to 256 GB (dedicated slot).
besides it can support Dual SIM (Nano-SIM, dual stand-by) .
the Gpu chip model is Adreno 308 and also the Chipset model used on this model is Snapdragon 425
The camera on the Huawei Atomu-L21 comes with and support 1080p video pixles.