Fix for using the official mysql image in composite stacks (eclipse-che#3049)

* Avoid passing empty array for command and entrypoint to Docker API
* Use official mysql docker image in the java-mysql stack

Signed-off-by: Kaloyan Raev <kaloyan.r@zend.com>

Author: kaloyan-raev

ide/che-core-ide-stacks/src/main/resources/stacks.json

@@ -46,7 +46,7 @@
             }
           },
           "recipe": {
-            "content": "services:\n db:\n  image: codenvy/mysql\n  environment:\n   MYSQL_DATABASE: petclinic\n   MYSQL_USER: petclinic\n   MYSQL_PASSWORD: password\n  mem_limit: 1073741824\n dev-machine:\n  image: codenvy/ubuntu_jdk8\n  mem_limit: 2147483648\n  depends_on:\n    - db",
+            "content": "services:\n db:\n  image: mysql\n  environment:\n   MYSQL_ROOT_PASSWORD: password\n   MYSQL_DATABASE: petclinic\n   MYSQL_USER: petclinic\n   MYSQL_PASSWORD: password\n  mem_limit: 1073741824\n dev-machine:\n  image: codenvy/ubuntu_jdk8\n  mem_limit: 2147483648\n  depends_on:\n    - db",
             "contentType": "application/x-yaml",
             "type": "compose"
           }

plugins/plugin-docker/che-plugin-docker-compose/src/main/java/org/eclipse/che/plugin/docker/compose/ComposeServiceImpl.java

@@ -130,9 +130,6 @@ public ComposeServiceImpl withBuild(BuildContext build) {
      * Override the default entrypoint.
      */
     public List<String> getEntrypoint() {
-        if (entrypoint == null) {
-            entrypoint = new ArrayList<>();
-        }
         return entrypoint;
     }
 
@@ -149,9 +146,6 @@ public ComposeServiceImpl withEntrypoint(List<String> entrypoint) {
      * Override the default command.
      */
     public List<String> getCommand() {
-        if (command == null) {
-            command = new ArrayList<>();
-        }
         return command;
     }
 

wsmaster/che-core-api-workspace/src/main/java/org/eclipse/che/api/environment/server/model/CheServiceImpl.java

@@ -137,9 +137,6 @@ public CheServiceImpl withBuild(CheServiceBuildContextImpl build) {
      * Override the default entrypoint.
      */
     public List<String> getEntrypoint() {
-        if (entrypoint == null) {
-            entrypoint = new ArrayList<>();
-        }
         return entrypoint;
     }
 
@@ -156,9 +153,6 @@ public CheServiceImpl withEntrypoint(List<String> entrypoint) {
      * Override the default command.
      */
     public List<String> getCommand() {
-        if (command == null) {
-            command = new ArrayList<>();
-        }
         return command;
     }