Hermes: Use Hermes commit sha as part of pod version

Summary:
Customize the Hermes version exposed to CocoaPods with one that refers to the facebook/hermes commit sha from which Hermes was built.

Changelog: [Internal]

Reviewed By: cortinico

Differential Revision: D36145140

fbshipit-source-id: 4ff7546d2335ea6642dd9b10f4b7a9aba260d550

sdks/hermes-engine.podspec

@@ -20,7 +20,7 @@ Pod::UI.puts '[Hermes] Hermes needs to be compiled, installing hermes-engine may
 
 Pod::Spec.new do |spec|
   spec.name        = "hermes-engine"
-  spec.version     = '1000.0.0'
+  spec.version     = "1000.0.0-#{hermes_tag_sha.slice(0,6)}"
   spec.summary     = "Hermes is a small and lightweight JavaScript engine optimized for running React Native."
   spec.description = "Hermes is a JavaScript engine optimized for fast start-up of React Native apps. It features ahead-of-time static optimization and compact bytecode."
   spec.homepage    = "https://hermesengine.dev"