Android's radial gradient shader only supports a single point circle radial gradient.
The Titanium radial gradient follows what is specified in the HTML Canvas specification
and is also the native behavior on iOS.
We should investigate a way to implement our own radial gradient that follows
the HTML Canvas specification or wait for Android to expose this type of gradient in the future.
It has been implemented in Skia, so it is possible this will be added in a future API level.