RN: Make `retry3` Portable in CI Scripts

Summary:
Moves the `retry3` utility function into its own file so that it can be reused in other steps that are not related to Android.

Changelog:
[Internal]

Reviewed By: rickhanlonii, cipolleschi

Differential Revision: D39889996

fbshipit-source-id: bf79cc19ad6178af0a0d8117a81116e0c32f4333

.circleci/Dockerfiles/scripts/run-android-docker-instrumentation-tests.sh

@@ -33,7 +33,7 @@ node cli.js bundle --platform android --dev true --entry-file ReactAndroid/src/a
 
 # build test APK
 # shellcheck disable=SC1091
-source ./scripts/android-setup.sh && NO_BUCKD=1 retry3 buck install ReactAndroid/src/androidTest/buck-runner:instrumentation-tests --config build.threads=1
+source ./scripts/android-setup.sh && NO_BUCKD=1 scripts/retry3 buck install ReactAndroid/src/androidTest/buck-runner:instrumentation-tests --config build.threads=1
 
 # run installed apk with tests
 node ./.circleci/Dockerfiles/scripts/run-android-ci-instrumentation-tests.js "$*"

.circleci/config.yml

@@ -617,7 +617,7 @@ jobs:
             if [[ ! -e ReactAndroid/src/androidTest/assets/AndroidTestBundle.js ]]; then
               echo "JavaScript bundle missing, cannot run instrumentation tests. Verify Build JavaScript Bundle step completed successfully."; exit 1;
             fi
-            source scripts/android-setup.sh && NO_BUCKD=1 retry3 timeout 300 buck build ReactAndroid/src/androidTest/buck-runner:instrumentation-tests --config build.threads=$BUILD_THREADS
+            source scripts/android-setup.sh && NO_BUCKD=1 scripts/retry3 timeout 300 buck build ReactAndroid/src/androidTest/buck-runner:instrumentation-tests --config build.threads=$BUILD_THREADS
 
       - run:
           name: Collect Test Results

scripts/android-setup.sh

@@ -94,21 +94,3 @@ function waitForAVD {
     echo "Skipping AVD-related test setup..."
   fi
 }
-
-function retry3 {
-  local n=1
-  local max=3
-  local delay=1
-  while true; do
-    "$@" && break || {
-      if [[ $n -lt $max ]]; then
-        ((n++))
-        echo "Command failed. Attempt $n/$max:"
-        sleep $delay;
-      else
-        echo "The command has failed after $n attempts." >&2
-        return 1
-      fi
-    }
-  done
-}

scripts/retry3

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+function retry3 {
+  local n=1
+  local max=3
+  local delay=1
+  while true; do
+    # shellcheck disable=SC2015
+    "$@" && break || {
+      if [[ $n -lt $max ]]; then
+        ((n++))
+        echo "Command failed. Attempt $n/$max:"
+        sleep $delay;
+      else
+        echo "The command has failed after $n attempts." >&2
+        return 1
+      fi
+    }
+  done
+}
+
+if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
+  retry3 "$@"
+fi