Just note that the Android native one-octave band graphic EQ would not have enough resolution for room EQ.
Parametric EQs for Android exist, but some may be a bit more difficult to get system-wide. I played earlier a bit with Android EQ options with a rooted FireTV stick running LineageOS and Viper4Android (
thread here) but in the end decided to go for miniDSP OpenDRC-DI instead for better ergonomics and reliability.
FireTV conversion was a nice little hobby project (and it worked!), but I found it was not very user-friendly nor a set-and-forget solution.
It also couldn't handle all of my sources.
With miniDSP it is much better, but still it means several boxes and a lot of connections (and still not covering all of my sources). So at the moment for me miniDSP Flex + stereo amp seems like a relatively simple solution in comparison.
Really I feel there are too few integrated stereo solutions on the market (e.g. all-in-one remote controlled preamp+DSP+DAC+amp) that incorporate some automated or manual parametric EQ capabilities - and those that do are
typically not cheap.
BTW, you might also wish to think what sources you want to connect (e.g. TV, PC, BT, turntable, streams...) before selecting your DAC/preamp/receiver, and also how you will switch between the various sources.