Add compatibility check badges to READMEs. (#8288)

Author: ylil93

packages/google-cloud-securitycenter/README.rst

@@ -1,6 +1,6 @@
 Python Client for Cloud Security Command Center API (`Alpha`_)
 ==============================================================
-|alpha| |pypi| |versions|
+|alpha| |pypi| |versions| |compat_check_pypi| |compat_check_github|
 
 `Cloud Security Command Center API`_: The public Cloud Security Command Center API.
 
@@ -13,6 +13,10 @@ Python Client for Cloud Security Command Center API (`Alpha`_)
    :target: https://pypi.org/project/google-cloud-securitycenter/
 .. |versions| image:: https://img.shields.io/pypi/pyversions/google-cloud-securitycenter.svg
    :target: https://pypi.org/project/google-cloud-securitycenter/
+.. |compat_check_pypi| image:: https://python-compatibility-tools.appspot.com/one_badge_image?package=google-cloud-securitycenter
+   :target: https://python-compatibility-tools.appspot.com/one_badge_target?package=google-cloud-securitycenter
+.. |compat_check_github| image:: https://python-compatibility-tools.appspot.com/one_badge_image?package=git%2Bgit%3A//github.com/googleapis/google-cloud-python.git%23subdirectory%3Dsecuritycenter
+   :target: https://python-compatibility-tools.appspot.com/one_badge_target?package=git%2Bgit%3A//github.com/googleapis/google-cloud-python.git%23subdirectory%3Dsecuritycenter
 .. _Alpha: https://github.com/googleapis/google-cloud-python/blob/master/README.rst
 .. _Cloud Security Command Center API: https://cloud.google.com/security-command-center
 .. _Client Library Documentation: https://googleapis.github.io/google-cloud-python/latest/securitycenter/index.html