RNCI: Migrate OSS CI to Flow DotSlash Binary (#50743)

Summary:
Pull Request resolved: #50743

Expose `--flowBinary` on React Native CI script.

Changelog:
[Internal]

Reviewed By: SamChou19815

Differential Revision: D73062734

fbshipit-source-id: 6501b6ff2976e4e7e0bbc1c6025205cde4169679

Author: yungsters

scripts/run-ci-javascript-tests.js

@@ -24,6 +24,7 @@ const numberOfMaxWorkers = argv.maxWorkers || 1;
 let exitCode;
 
 const JEST_BINARY = argv.jestBinary || './node_modules/.bin/jest';
+const FLOW_BINARY = argv.flowBinary;
 const YARN_BINARY = argv.yarnBinary || 'yarn';
 
 function describe(message) {
@@ -55,7 +56,11 @@ try {
   }
 
   describe('Test: Flow check');
-  if (exec(`${YARN_BINARY} run flow-check`).code) {
+  const flowCommand =
+    FLOW_BINARY == null
+      ? `${YARN_BINARY} run flow-check`
+      : `${FLOW_BINARY} check`;
+  if (exec(flowCommand).code) {
     echo('Failed to run flow.');
     exitCode = 1;
     throw Error(exitCode);