message: Add one more directory level in default merger type package name
  Summary:
  Putting shapes with a default package name under `com.facebook.redex`.
  This name avoids polluting the root directory for code size attrition analysis.
diff: @@ -195,7 +195,7 @@ std::string get_merger_package_name(const DexType* type) {
  // loader.
  if (boost::starts_with(pkg_name, "Landroid") ||
  boost::starts_with(pkg_name, "Ldalvik")) {
  - return "Lcom/facebook";
  + return "Lcom/facebook/redex";
  }
  return pkg_name;
  }
  