Block submissions with topics

Bug: b/361082477
Change-Id: I829916f0990057fe79a2c086129f190fdfa0f88f
Reviewed-on: https://bluetooth-review.googlesource.com/c/All-Projects/+/2180
Reviewed-by: Ted Pudlik <tpudlik@google.com>

project.config

diff --git a/project.config b/project.config
index 7a08d23..135575a 100644
--- a/project.config
+++ b/project.config
@@ -102,3 +102,8 @@
 	applicableIf = -path:\"^.*$\"
 	submittableIf = is:false
 	canOverrideInChildProjects = false
+[submit-requirement "Topics-Not-Supported"]
+	description = A topic is set on this change but topics are not supported on this host.
+	applicableIf = -topic:\"\"
+	submittableIf = is:false
+	canOverrideInChildProjects = false