That wholly depends on the specific Android device you are using, and/or optimised Android audio app you choose.
For most Android devices, one app that can bypass Android's internal resampling audio engine is
USB Audio Player Pro (henceforth UAPP).
This has support for multiple audio streaming services, home network, and UPnP/DLNA support.
Sadly, no ROON support currently.
UAPP is widely popular and will bypass Android audio engine, provided you use the app for music playback and adjust any settings (many, including settings for bit-perfect mode!).
You can add MQA decoding, external EQ, and other add-on's as you require too.
Otherwise, you may need specialist Android devices that have in-built apps or heavily modified operating systems to bypass Android's default audio engine.
FiiO, iBasso, Cayin, and many more, allow this, though only a few allow near full Android experience (FiiO on latest digital audio players, for example).
In regards to T+A Solitaire T into your device via USB-C OTG cable, I'm not actually sure.
My understanding is that music is first run through typical Android audio engine first, then that data is sent out to a DAC. If using USB-C OTG mode, then an external DAC will take over (such as Solitaire T's ESS Sabre ES9218 chip).
If you are not using a specialist Android device, then you may need to use something like USB Audio Player PRO to make sure default Android audio engine is bypassed (so only using UAPP audio engine), and this data signal can then go to a DAC, whether internal, or external via USB-C OTG.
As far as I am aware, the Roon app for Android does not bypass default Android audio engine
except on specialist Android devices.
Hope this helps!