CTS tests for major:minor of /dev/random and /dev/urandom.

These tests assert that /dev/random and /dev/urandom are backed by
the correct parts of the Linux RNG kernel driver.

Bug: 10394220

Conflicts:
	tests/tests/security/jni/Android.mk

(cherry picked from commit c277854a)

Change-Id: I415309c6b14f2e38062d00c365ab9e2d2a881ae9