[15] RFR JDK-8246613: Choose the default SecureRandom algo based on registration ordering

[Valerie Peng]

Hi,

Could someone help reviewing this fix? This change keep tracks of the 
first registered SecureRandom algorithm and returns it upon the request 
of SecureRandom class.

Bug: https://bugs.openjdk.java.net/browse/JDK-8246613

Webrev: http://cr.openjdk.java.net/~valeriep/8246613/webrev.00/

Thanks,

Valerie