Append slash to copy destination in adService Dockerfile (#1530)

As described in Docker docs:

If multiple <src> resources are specified, either directly or due to the use of a wildcard, then <dest> must be a directory, and it must end with a slash /.

Having no slash at the end of this command may make Docker build fail under certain circumstances.

Co-authored-by: Austin Parker <austin@ap2.io>

src/adservice/Dockerfile

@@ -6,7 +6,7 @@ FROM eclipse-temurin:21-jdk as builder
 
 WORKDIR /usr/src/app/
 
-COPY ./src/adservice/gradlew* ./src/adservice/settings.gradle* ./src/adservice/build.gradle .
+COPY ./src/adservice/gradlew* ./src/adservice/settings.gradle* ./src/adservice/build.gradle ./
 COPY ./src/adservice/gradle ./gradle
 
 RUN ./gradlew