FIS: disable IID migration tests by default (#6619)

* FIS: disable IID migration tests by default

* remove redundant env variable

* Fix merge errors

.github/workflows/installations.yml

@@ -36,7 +36,6 @@ jobs:
     - name: Build and test
       run: |
        export FIS_INTEGRATION_TESTS_REQUIRED=${{ steps.secrets.outputs.val }}
-       export FIS_ALLOWS_INCOMPATIBLE_IID_VERSION="1"
        scripts/third_party/travis/retry.sh scripts/pod_lib_lint.rb FirebaseInstallations.podspec \
          --platforms=${{ matrix.target }} --ignore-local-podspecs=FirebaseInstanceID.podspec
 
@@ -129,7 +128,6 @@ jobs:
     - name: PodLibLint Installations Cron
       run: |
        export FIS_INTEGRATION_TESTS_REQUIRED=${{ steps.secrets.outputs.val }}
-       export FIS_ALLOWS_INCOMPATIBLE_IID_VERSION="1"
        scripts/third_party/travis/retry.sh scripts/pod_lib_lint.rb FirebaseInstallations.podspec \
          --platforms=${{ matrix.target }} ${{ matrix.flags }} \
          --ignore-local-podspecs=FirebaseInstanceID.podspec

FirebaseInstallations.podspec

@@ -54,12 +54,16 @@ Pod::Spec.new do |s|
 
   s.test_spec 'unit' do |unit_tests|
     unit_tests.platforms = {:ios => '9.0', :osx => '10.12', :tvos => '10.0'}
-    unit_tests.source_files = base_dir + 'Tests/Unit/**/*.[mh]',
-                              base_dir + 'Tests/Utils/**/*.[mh]'
+    unit_tests.source_files = base_dir + 'Tests/Unit/*.[mh]',
+                              base_dir + 'Tests/Utils/*.[mh]'
     unit_tests.resources = base_dir + 'Tests/Fixture/**/*'
     unit_tests.requires_app_host = true
     unit_tests.dependency 'OCMock'
-    unit_tests.dependency 'FirebaseInstanceID', '~> 4.2.0' # The version before FirebaseInstanceID updated to use FirebaseInstallations under the hood.
+
+    if ENV['FIS_IID_MIGRATION_TESTING'] && ENV['FIS_IID_MIGRATION_TESTING'] == '1' then
+      unit_tests.source_files += base_dir + 'Tests/Unit/IIDStoreTests/*.[mh]'
+      unit_tests.dependency 'FirebaseInstanceID', '~> 4.2.0' # The version before FirebaseInstanceID updated to use FirebaseInstallations under the hood.
+    end
 
   end