Support specifying the location of the Oculus SDK through the global gradle.properties file; or in Android Studio via File->Settings->Path Variables.
Support specifying the location of the Oculus SDK through
the global gradle.properties file; or in Android Studio via
File->Settings->Path Variables.

Set OVR_MOBILE_SDK to point to the directory of the Oculus
Mobile SDK. This will make having ovr_sdk_mobile under GearVRf
optional.

GearVRf-DCO-1.0-Signed-off-by: Mihail Marinov <m.marinov@samsung.com>

NolaDonato/GearVRf,ragner/GearVRf,roshanch/GearVRf,bsmr-android/GearVRf,Samsung/GearVRf,xcaostagit/GearVRf,rahul27/GearVRf,NolaDonato/GearVRf,parthmehta209/GearVRf,ragner/GearVRf,thomasflynn/GearVRf,bsmr-android/GearVRf,NolaDonato/GearVRf,thomasflynn/GearVRf,mwitchwilliams/GearVRf,mwitchwilliams/GearVRf,roshanch/GearVRf,aglne/GearVRf,aglne/GearVRf,Samsung/GearVRf,Samsung/GearVRf,bsmr-android/GearVRf,Samsung/GearVRf,thomasflynn/GearVRf,aglne/GearVRf,thomasflynn/GearVRf,xcaostagit/GearVRf,ragner/GearVRf,ragner/GearVRf,ragner/GearVRf,parthmehta209/GearVRf,mwitchwilliams/GearVRf,Samsung/GearVRf,NolaDonato/GearVRf,aglne/GearVRf,xcaostagit/GearVRf,Samsung/GearVRf,NolaDonato/GearVRf,xcaostagit/GearVRf,mwitchwilliams/GearVRf,aglne/GearVRf,thomasflynn/GearVRf,bsmr-android/GearVRf,rahul27/GearVRf,rahul27/GearVRf,Samsung/GearVRf,aglne/GearVRf,NolaDonato/GearVRf,xcaostagit/GearVRf,aglne/GearVRf,bsmr-android/GearVRf,bsmr-android/GearVRf,thomasflynn/GearVRf,mwitchwilliams/GearVRf,NolaDonato/GearVRf,rahul27/GearVRf,roshanch/GearVRf,parthmehta209/GearVRf,parthmehta209/GearVRf,parthmehta209/GearVRf,aglne/GearVRf,thomasflynn/GearVRf,xcaostagit/GearVRf,roshanch/GearVRf,ragner/GearVRf,rahul27/GearVRf,roshanch/GearVRf,rahul27/GearVRf