snappy rpms break eden cmake build

Summary: On centos stream 8 the system snappy rpms break edenfs cmake build, so build it from the manifest instead

Reviewed By: HarveyHunt

Differential Revision: D32693521

fbshipit-source-id: 4cc830d72cea27b6d15e55685038bb216377c9b9

build/fbcode_builder/manifests/snappy

 [manifest]
 name = snappy
 
-[rpms]
-snappy
-snappy-devel
-
 [debs]
 libsnappy-dev