fix: update Dockerfile to use JRE (GoogleCloudPlatform#5454)

Author: averikitsch

run/helloworld/Dockerfile

@@ -31,7 +31,7 @@ RUN mvn package -DskipTests
 # It's important to use OpenJDK 8u191 or above that has container support enabled.
 # https://hub.docker.com/r/adoptopenjdk/openjdk8
 # https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds
-FROM adoptopenjdk/openjdk11:alpine-slim
+FROM adoptopenjdk/openjdk11:alpine-jre
 
 # Copy the jar to the production image from the builder stage.
 COPY --from=builder /app/target/helloworld-*.jar /helloworld.jar

run/image-processing/Dockerfile

@@ -17,7 +17,7 @@
 # Use AdoptOpenJDK for base image.
 # It's important to use OpenJDK 8u191 or above that has container support enabled.
 # https://hub.docker.com/r/adoptopenjdk/openjdk11
-FROM adoptopenjdk/openjdk11:alpine-slim
+FROM adoptopenjdk/openjdk11:alpine-jre
 
 # Install Imagemagick into the container image.
 # For more on system packages review the system packages tutorial.

run/system-package/Dockerfile

@@ -16,7 +16,7 @@
 # [START run_system_package_dockerfile]
 # Use the Official OpenJDK image for a lean production stage of our multi-stage build.
 # https://hub.docker.com/r/adoptopenjdk/openjdk11/
-FROM adoptopenjdk/openjdk11:alpine
+FROM adoptopenjdk/openjdk11:alpine-jre
 
 RUN apk --no-cache add graphviz ttf-ubuntu-font-family
 # [END run_system_package_dockerfile]