Updating Devcontainer Dockerfile so the vscode user can run bootstrap (#193224)

## Summary

There was a permissions issue running bootstrap in the devContainer on
Mac.

.devcontainer/.env.template

@@ -1,4 +1,5 @@
 # /bin/bash or /bin/zsh (oh-my-zsh is installed by default as well)
 SHELL=/bin/bash
-# Switch to 1 to enable FIPS environment, any other value to disable
+# Switch to 1 to enable FIPS environment, any other value to disable,
+# then close and reopen a new terminal to setup the environment
 FIPS=0

.devcontainer/Dockerfile

@@ -49,6 +49,9 @@ WORKDIR ${KBN_DIR}
 
 # Node and NVM setup
 COPY .node-version /tmp/
+
+USER vscode
+
 RUN mkdir -p $NVM_DIR && \
   curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/${NVM_VERSION}/install.sh | bash && \
   . "$NVM_DIR/nvm.sh" && \
@@ -61,6 +64,8 @@ RUN mkdir -p $NVM_DIR && \
   echo "source $NVM_DIR/nvm.sh" >> ${HOME}/.zshrc  && \
   chown -R 1000:1000 "${HOME}/.npm"
 
+USER root
+
 # Reload the env everytime a new shell is opened incase the .env file changed.
 RUN echo "source $KBN_DIR/.devcontainer/scripts/env.sh" >> ${HOME}/.bashrc && \
   echo "source $KBN_DIR/.devcontainer/scripts/env.sh" >> ${HOME}/.zshrc