We should add detection support for ARMv8 in the JmeAndroidSystem.
I have a 64-bit ARMv8 phone which reports the following.
os.name = linux
os.arch = aarch64
This indicates a 64 bit ARMv8.
Implementation wise we should probably add a new platform Android_ARM8 as well as some more detection code in both JmeAndroidSystem to detect this platform and expand is64Bit() in JmeSystemDelegate to return true for aarch64 and false for aarch32.
Resolves #378, adding support for detecting ARMv8 on Android.