Web3j: Random & Android

[ligi]

As Web3j is also intended to be used on Android - a secure random implementation should be used like:
https://github.com/bitcoinj/bitcoinj/blob/master/core/src/main/java/org/bitcoinj/crypto/LinuxSecureRandom.java

also see:
https://github.com/bitcoinj/bitcoinj/blob/master/core/src/main/java/org/bitcoinj/core/ECKey.java#L136

and:

https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html

[conor10]

Thanks for highlighting this @ligi, much appreciated.

[conor10]

Done.

[ligi]

thanks!