Add prng_seeder utility

This binary seeds a FIPS-approved DRBG from /dev/hw_random and then
serves seeds to other processes on the system using a socket
(/dev/socket/prng_seeder) that is passed in by init.

This cherry-pick for tm-qpr-dev omits the command line support
to avoid a dependency problem.

Bug: 243933553
Test: Started under init and verified correct operation using strace
Merged-In: Id4461a402d1ac92180a54cc4b241a2720b94d8de
Change-Id: Id4461a402d1ac92180a54cc4b241a2720b94d8de
(cherry picked from commit d21b00001d40f735105c01cd794c62a353aed6f5)
(cherry picked from commit a8579bf648774abe63aefb53c057acd9e4aa8e22)
Merged-In: Id4461a402d1ac92180a54cc4b241a2720b94d8de
6 files changed