Fix: Suppress RuntimeWarnings in advanced_operations tests

I've suppressed RuntimeWarnings that were occurring in several test files within the examples/advanced_operations/tests directory.

The warnings were of the form:
"RuntimeWarning: 'module_name' found in sys.modules after import of package 'examples.advanced_operations', but prior to execution of 'module_name'; this may result in unpredictable behaviour"

These warnings were triggered by the use of `runpy.run_module` to test the main execution path of the example scripts. My investigation showed that the warnings are likely a benign side effect of how `runpy` interacts with already-loaded packages and modules within the test execution context.

Here's what I did:
1. I investigated the cause of the warnings.
2. I attempted to resolve them by modifying import statements (e.g., removing redundant imports, changing import locations), but these approaches did not eliminate the warnings.
3. I determined that the most appropriate solution was to suppress these specific warnings as they did not indicate an underlying bug and all tests were passing.
4. I applied warning suppression using Python's `warnings` module:
    - I imported the `warnings` module in each affected test file.
    - I wrapped the `runpy.run_module` calls within a `warnings.catch_warnings()` context manager.
    - Inside this context, I used `warnings.filterwarnings()` to ignore the specific `RuntimeWarning` based on its message content and category.
5. I applied this fix to:
    - examples/advanced_operations/tests/test_add_call_ad.py
    - examples/advanced_operations/tests/test_add_display_upload_ad.py
    - examples/advanced_operations/tests/test_add_dynamic_search_ads.py
    - examples/advanced_operations/tests/test_add_performance_max_campaign.py
    - examples/advanced_operations/tests/test_add_responsive_search_ad_full.py
6. I confirmed with multiple test runs that all tests continue to pass and the specified warnings are no longer displayed.

Author: google-labs-jules[bot]