google.cloud.iap connection has scp_if_ssh set to smart

##### SUMMARY

Latest version Ansible documentation for Google Cloud IAP connection has an error regarding the default setting of scp_if_ssh to "smart". The error can be seen at: https://docs.ansible.com/ansible/latest/collections/google/cloud/iap_connection.html#ansible-collections-google-cloud-iap-connection

1 validation error for PluginDocSchema
doc -> options -> scp_if_ssh
Value error, Invalid value 'smart' for "default": The value 'smart' is not a valid boolean. Valid booleans include: 0, 1, 'n', 'off', '1', 'false', 'true', 'f', 'yes', 'no', 'y', 't', 'on', '0' (type=value_error; error=Invalid value 'smart' for "default": The value 'smart' is not a valid boolean. Valid booleans include: 0, 1, 'n', 'off', '1', 'false', 'true', 'f', 'yes', 'no', 'y', 't', 'on', '0')

Same error exists for version 11 and devel.

##### ISSUE TYPE
- Documentation Report

##### COMPONENT NAME

connection plugin: google.cloud.iap connection
setting: scp_if_ssh
##### ANSIBLE VERSION

```
ansible [core 2.19.2]
config file = None
configured module search path = ['/Users/vlad/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
ansible python module location = /opt/homebrew/Cellar/ansible/12.0.0/libexec/lib/python3.13/site-packages/ansible
ansible collection location = /Users/vlad/.ansible/collections:/usr/share/ansible/collections
executable location = /opt/homebrew/bin/ansible
python version = 3.13.7 (main, Aug 14 2025, 11:12:11) [Clang 17.0.0 (clang-1700.0.13.3)] (/opt/homebrew/Cellar/ansible/12.0.0/libexec/bin/python)
jinja version = 3.1.6
pyyaml version = 6.0.2 (with libyaml v0.2.5)
```

Start at the linked Google Cloud IAP connection documentation page and locate the scp_if_ssh option. Check the displayed default against the boolean validation error, then update the documentation and verify the same issue is corrected for version 11 and devel.

Written by the indexing model from the issue text.