Hey ZTE Axon 7 Treble group,
Ok I've been working on this VoLTE for a while now on spare time. I've had multiple devs from other forums test it out on phones for their GSI. They confirmed it's working. I've also had multiple testers from the Axon 7 Trebleshoot group test it and confirm it's working. I know for sure it works on T-Mobile/T-Mobile based carriers but don't know for other carriers. Here is the modified package.
1. Phh-based GSI
2. TWRP Treble
3. System/Vendor with Decryption level support
4. Compatible carrier that supports VoLTE
5. No complaining about the process to install because trust me it was alot more work for me to modify the apks internally and put together.
1. Extract VoPackage zip.
2. Install ims.apk in the package.
3. Reboot, let it fully boot and see if you have VoLTE, if not go to next step.
4. Reboot to TWRP.
5. Mount /system and /vendor.
6. Flash VoMod zip.
7. Reboot and check your ims registration by dialing *#*#4636#*#* and going to the 3 dots in the top right corner to check IMS Service Status. It should say registered.
Do the same installation of Version 1.
Added Ims Settings to /system/app for improved stability.
@phhusson for his great work in treble development.
@raystef66 for file structure implementation.
Special thanks to also the Axon7 (s)GSI Trebleshoot Testers!