OpenSSLRandom: throw exception when seed == null

Even though we don't really pay attention to the seed given to us, we
should throw NullPointerException since someone calling #setSeed(byte[])
with a null parameter is probably making a mistake anyway.

Bug: 20521744
Change-Id: Ib274c4abc059b6e4d3eb6cf95d30fec605284948
1 file changed