Use ibm-semeru-runtimes:open-8u402-b06-jdk-focal. (#162)

- Update parent image to ibm-semeru-runtimes:open-8u402-b06-jdk-focal to get latest vulnerability fixes.
diff --git a/core/java8/CHANGELOG.md b/core/java8/CHANGELOG.md
index 40599cf..c88d80c 100644
--- a/core/java8/CHANGELOG.md
+++ b/core/java8/CHANGELOG.md
@@ -20,7 +20,7 @@
 # Java 8 OpenWhisk Runtime Container
 
 # next Release
-- use `ibm-semeru-runtimes:open-8u392-b08-jdk-focal` as baseimage
+- use `ibm-semeru-runtimes:open-8u402-b06-jdk-focal` as baseimage
 
 # 1.19.0
  - use `ibm-semeru-runtimes:open-8u382-b05-jdk-focal` as baseimage
diff --git a/core/java8/Dockerfile b/core/java8/Dockerfile
index dd7a07b..24dba5f 100644
--- a/core/java8/Dockerfile
+++ b/core/java8/Dockerfile
@@ -16,7 +16,7 @@
 #
 
 # Use AdoptOpenJDK's JDK8, OpenJ9, ubuntu
-FROM ibm-semeru-runtimes:open-8u392-b08-jdk-focal
+FROM ibm-semeru-runtimes:open-8u402-b06-jdk-focal
 
 RUN rm -rf /var/lib/apt/lists/* \
     && apt-get clean \
diff --git a/core/java8actionloop/CHANGELOG.md b/core/java8actionloop/CHANGELOG.md
index 4f0bcab..2e0f1a0 100644
--- a/core/java8actionloop/CHANGELOG.md
+++ b/core/java8actionloop/CHANGELOG.md
@@ -20,7 +20,7 @@
 # Java 8 OpenWhisk Runtime Container
 
 # next Release
-- use `ibm-semeru-runtimes:open-8u392-b08-jdk-focal` as baseimage
+- use `ibm-semeru-runtimes:open-8u402-b06-jdk-focal` as baseimage
 
 # 1.19.0
  - use `ibm-semeru-runtimes:open-8u382-b05-jdk-focal` as baseimage
diff --git a/core/java8actionloop/Dockerfile b/core/java8actionloop/Dockerfile
index d06fbe3..447ec54 100644
--- a/core/java8actionloop/Dockerfile
+++ b/core/java8actionloop/Dockerfile
@@ -34,7 +34,7 @@
   && GO111MODULE=on CGO_ENABLED=0 go build -o /bin/proxy
 
 # Use AdoptOpenJDK's JDK8, OpenJ9, ubuntu
-FROM ibm-semeru-runtimes:open-8u392-b08-jdk-focal
+FROM ibm-semeru-runtimes:open-8u402-b06-jdk-focal
 
 # select the builder to use
 ARG GO_PROXY_BUILD_FROM=release