Fix ios_add2app Podfile (#131263)

Fixes:

* flutter/flutter#131261

Author: dcharkes

dev/integration_tests/ios_add2app_life_cycle/Podfile

@@ -10,7 +10,7 @@ target 'ios_add2app' do
 end
 
 target 'ios_add2appTests' do
-  install_flutter_engine_pod
+  install_flutter_engine_pod(flutter_application_path)
   pod 'EarlGreyTest'
 end