Use packageManager defined in package.json when yarn-version is n…

…ot specified in yarn action

yarn/action.yml

@@ -1,9 +1,9 @@
-name: 'Build Image w/ Yarn'
-description: 'Build an image using yarn'
-author: 'GarnerCorp'
+name: "Build Image w/ Yarn"
+description: "Build an image using yarn"
+author: "GarnerCorp"
 branding:
-  icon: 'aperture'
-  color: 'purple'
+  icon: "aperture"
+  color: "purple"
 inputs:
   checkout:
     description: Whether or not to checkout the repository you are currently working in
@@ -27,8 +27,7 @@ inputs:
     default: "18"
     required: false
   yarn-version:
-    description: "Yarn version to use"
-    default: "3.6.4"
+    description: "Yarn version to use, if not specified, the version defined in package.json will be used"
     required: false
   working-directory:
     description: "Directory containing package.json"
@@ -75,7 +74,7 @@ inputs:
     required: false
 
 runs:
-  using: 'composite'
+  using: "composite"
   steps:
     - name: Validate inputs (yarn berry)
       if: ${{ !inputs.google-credentials-json != !inputs.google-cloud-sdk-version || (inputs.yarn-version >= '2' && !inputs.npm-username != !inputs.npm-password) }}
@@ -111,14 +110,17 @@ runs:
     - name: Use Yarn Berry
       shell: bash
       if: inputs.yarn-version >= '2'
+      working-directory: ${{ inputs.working-directory }}
       env:
         yarn_version: ${{ inputs.yarn-version }}
       run: |
         $GITHUB_ACTION_PATH/../scripts/add-matchers.sh
         if ! command -v yarn >/dev/null; then
           corepack prepare yarn@stable --activate
         fi
-        yarn set version "$yarn_version"
+        if [ -n "$yarn_version" ]; then
+          yarn set version "$yarn_version"
+        fi
 
     - name: Ensure yarn is available
       shell: bash