Got it working!
Turns out that I needed to use the “experimental” check box of “Enable Gradle instead of Ant”, found under Platforms → Android:
I’ve read that in 4.18, the default for Android will be gradle instead of ant (so this means ant will no longer be supported?), so this might explain why this checkbox fixed my build/packaging errors.
Although, I ran this issue when my game loaded on device:
I had to turn off Multi-View & Multi-View Direct. All was fine then.
Things seem to be working now on Daydream at least. I’m nervous to switch back to my Oculus/GearVR version…