Although the CPU from your phone is 64-bit, it's probably running a 32 bit version of Android (which is pretty common on low and mid range devices) and there's nothing you can do. If you are lucky, there *might* be a custom ROM with 64-bit support available for your phone but I don't think it's worth it, as even if you could install and run Dolphin the performance would be pretty bad as the Snapdragon 450 from your J8 is severely underpowered for GC/Wii emulation (keep in mind that even current flagships with high end Snapdragon 855 SoC still struggles with Dolphin depending of the game)...
Avell A70 MOB: Core i7-11800H, GeForce RTX 3060, 16 GB DDR4-3200, Windows 11 (Insider Preview)
ASRock Z97M OC Formula: Pentium G3258, GeForce GT 440, 16 GB DDR3-1600, Windows 10 (22H2)
ASRock Z97M OC Formula: Pentium G3258, GeForce GT 440, 16 GB DDR3-1600, Windows 10 (22H2)