Splits test_docker into smaller steps (#32215)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/32215

Currently `test_docker` is the biggest offender in terms of time consumed
on CI (~70 minutes). I'm splitting it in smaller steps to let us investigate better
what is going on.

Changelog:
[General] [Changed] - Splits test_docker into smaller steps

Reviewed By: ShikaSD

Differential Revision: D30958906

fbshipit-source-id: 2a80535afe77f98427dd0d38e66c6de3fdf80188

.circleci/config.yml

@@ -554,19 +554,22 @@ jobs:
   # -------------------------
   #    JOBS: Test Docker
   # -------------------------
-  test_docker:
+  test_docker_android:
     machine: true
     steps:
       - checkout
       - run:
-          name: Build Docker container for Android RNTester App
+          name: Configure Node
           command: |
             source ~/.bashrc
             nvm i node
-            npm i -g yarn
             echo y | npx envinfo@latest
-            yarn run docker-setup-android
-            yarn run docker-build-android
+      - run:
+          name: Pulls down the React Native Community Android Docker image
+          command: npm run docker-setup-android
+      - run:
+          name: Builds the Docker image with a compiled instance of the test app
+          command: npm run docker-build-android
 
   # -------------------------
   #    JOBS: Windows
@@ -774,7 +777,7 @@ workflows:
           filters:
             branches:
               ignore: gh-pages
-      - test_docker:
+      - test_docker_android:
           filters:
             branches:
               ignore: gh-pages