Fix internal test podfile

Author: jonsimantov

firestore/integration_test_internal/Podfile

@@ -1,17 +1,18 @@
 source 'https://github.com/CocoaPods/Specs.git'
 platform :ios, '10.0'
 # Cloud Firestore internal test application.
+use_frameworks! :linkage => :static
 
 target 'integration_test' do
   platform :ios, '10.0'
-  pod 'Firebase/Firestore', '8.15.0'
-  pod 'Firebase/Auth', '8.15.0'
+  pod 'Firebase/Firestore', '9.0.0'
+  pod 'Firebase/Auth', '9.0.0'
 end
 
 target 'integration_test_tvos' do
   platform :tvos, '12.0'
-  pod 'Firebase/Firestore', '8.15.0'
-  pod 'Firebase/Auth', '8.15.0'
+  pod 'Firebase/Firestore', '9.0.0'
+  pod 'Firebase/Auth', '9.0.0'
 end
 
 post_install do |installer|