Can't use openvr dependency on Android API 14

[dxdxdt]

I tried to add this library on gradle.build to use it on an Android app. It didn't work. Gradle sync fails because openvr requires API 22 runtimes (not sure if it was sync or build that fails.)

So, I looked into the code and found that not much of the code was using openvr. After realising that, I removed a few lines of code to compile without openvr dependency. Gradle synced, the app was built, and obviously, glm worked on the app without any problem.

For anyone having the same problem as I did, refer to my forked repo if you want to see what parts of the code I modified/removed. There are still many Android 4.0 phones out there. My phone is the very example.