chore: remove initialize terraservice in fl (#80)

Remove the 'initialize' terraservice in the Federated Learning use case
because the core platform 'initialize' terraservice takes care of
configuring backends for use cases after #71 is merged.

The only task implemented in the use case 'initialize' terraservice was
to initialize backend configuration, so we don't need it anymore.

Also, simplify provisioning and teardown scripts because we don't need
two different terraform init commands anymore because now all the
terraservices in the use case work with a remote backend.

platforms/gke/base/use-cases/federated-learning/common.sh

@@ -31,26 +31,13 @@ FEDERATED_LEARNING_USE_CASE_TERRAFORM_DIR="${FEDERATED_LEARNING_USE_CASE_DIR}/te
 # shellcheck disable=SC2034 # Variable is used in other scripts
 FEDERATED_LEARNING_SHARED_CONFIG_DIR="${FEDERATED_LEARNING_USE_CASE_TERRAFORM_DIR}/_shared_config"
 
-# shellcheck disable=SC2034 # Variable is used in other scripts
-FEDERATED_LEARNING_USE_CASE_INITIALIZE_SERVICE_DIR="${FEDERATED_LEARNING_USE_CASE_TERRAFORM_DIR}/initialize"
-
 # shellcheck disable=SC2034 # Variable is used in other scripts
 federated_learning_terraservices=(
   "initialize"
   "container_image_repository"
   "private_google_access"
 )
 
-TERRAFORM_INIT_COMMAND=(
-  terraform init
-)
-
-# shellcheck disable=SC2034 # Variable is used in other scripts
-TERRAFORM_INIT_BACKEND_CONFIG_COMMAND=(
-  "${TERRAFORM_INIT_COMMAND[@]}"
-  -backend-config="backend.config"
-)
-
 # shellcheck disable=SC2034 # Variable is used in other scripts
 TERRAFORM_CLUSTER_CONFIGURATION=(
 )
@@ -62,19 +49,8 @@ apply_or_destroy_terraservice() {
   local operation_mode
   operation_mode="${2:-"not set"}"
 
-  local -a TERRASERVICE_TERRAFORM_INIT_COMMAND
-  TERRASERVICE_TERRAFORM_INIT_COMMAND=(
-    "${TERRAFORM_INIT_BACKEND_CONFIG_COMMAND[@]}"
-  )
-  if [ "${terraservice:-}" == "initialize" ]; then
-    TERRASERVICE_TERRAFORM_INIT_COMMAND=(
-      "${TERRAFORM_INIT_COMMAND[@]}"
-    )
-  fi
-  echo "Terraform init command for ${terraservice}: ${TERRASERVICE_TERRAFORM_INIT_COMMAND[*]}"
-
   cd "${FEDERATED_LEARNING_USE_CASE_TERRAFORM_DIR}/${terraservice}" &&
-    "${TERRASERVICE_TERRAFORM_INIT_COMMAND[@]}"
+    terraform init
 
   echo "Current working directory: $(pwd)"