Add msalautomationapp validation job to build-consumers pipeline, Fixes AB#3587778 (#3106)

This pull request adds a new validation job for the MSAL Automation App
to the Azure Pipelines configuration. This ensures that the automation
app is built and validated as part of the pull request process,
improving test coverage and reliability for changes impacting this
component.

**Pipeline enhancements:**

* Added a new `msalAutomationAppValidation` job to
`azure-pipelines/pull-request-validation/build-consumers.yml` that
checks out the MSAL repository and its submodules, ensures the proper
branch is used for the common submodule, sets up automation
certificates, and assembles the `msalautomationapp` using Gradle.


[AB#3587778](https://identitydivision.visualstudio.com/fac9d424-53d2-45c0-91b5-ef6ba7a6bf26/_workitems/edit/3587778)

---------

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Author: 3 people

azure-pipelines/pull-request-validation/build-consumers.yml

@@ -132,6 +132,37 @@ stages:
         tasks: msal:testLocalDebugUnitTest -Plabtest -PlabSecret=$(LabVaultAppCert) -ProbolectricSdkVersion=${{variables.robolectricSdkVersion}} -PmockApiUrl=$(MOCK_API_URL) -PnativeAuthConfigString=$(NATIVE_AUTH_CONFIG_STRING)
         jdkArchitecture: x64
         jdkVersionOption: "1.17"
+  # msalautomationapp
+  - job: msalAutomationAppValidation
+    displayName: MSAL Automation App
+    dependsOn:
+      - setupBranch
+    variables:
+      commonBranch: $[ dependencies.setupBranch.outputs['setvarStep.commonBranch'] ]  # map in the variable
+    condition: and( succeeded(), not(contains(variables['prLabels'], variables['skipConsumerValidationLabel'])) )
+    steps:
+    - checkout: msal
+      displayName: Checkout msal repository
+      clean: true
+      submodules: recursive
+      persistCredentials: True
+    - task: CmdLine@2
+      displayName: Checkout common submodule $(commonBranch)
+      inputs:
+        script: |
+          git fetch
+          git checkout $(commonBranch)
+          git pull
+          git status
+          git rev-parse HEAD
+        workingDirectory: $(Agent.BuildDirectory)/s/common
+    - template: ../templates/steps/automation-cert.yml
+    - task: Gradle@3
+      displayName: Assemble msalautomationapp
+      inputs:
+        jdkArchitecture: x64
+        jdkVersionOption: "1.17"
+        tasks: clean msalautomationapp:assembleLocal
   # broker
   - job: brokerValidation
     displayName: Broker