chore: add container cmd check (#1306)

# What does this PR do?
[Provide a short summary of what this PR does and why. Link to relevant
issues if applicable.]

[//]: # (If resolving an issue, uncomment and update the line below)
[//]: # (Closes #[issue-number])

## Test Plan
[Describe the tests you ran to verify your changes with result
summaries. *Provide clear instructions so the plan can be easily
re-executed.*]

[//]: # (## Documentation)

Signed-off-by: reidliu <reid201711@gmail.com>
Co-authored-by: reidliu <reid201711@gmail.com>

llama_stack/distribution/build_container.sh

@@ -48,6 +48,9 @@ CONTAINER_OPTS=${CONTAINER_OPTS:-}
 
 TEMP_DIR=$(mktemp -d)
 
+SCRIPT_DIR=$(dirname "$(readlink -f "$0")")
+source "$SCRIPT_DIR/common.sh"
+
 add_to_container() {
   output_file="$TEMP_DIR/Containerfile"
   if [ -t 0 ]; then
@@ -58,6 +61,12 @@ add_to_container() {
   fi
 }
 
+# Check if container command is available
+if ! is_command_available $CONTAINER_BINARY; then
+  printf "${RED}Error: ${CONTAINER_BINARY} command not found. Is ${CONTAINER_BINARY} installed and in your PATH?${NC}" >&2
+  exit 1
+fi
+
 # Update and install UBI9 components if UBI9 base image is used
 if [[ $container_base == *"registry.access.redhat.com/ubi9"* ]]; then
   add_to_container << EOF
@@ -212,7 +221,7 @@ if [ "$USE_COPY_NOT_MOUNT" != "true" ]; then
   fi
 fi
 
-if command -v selinuxenabled &>/dev/null && selinuxenabled; then
+if is_command_available selinuxenabled && selinuxenabled; then
   # Disable SELinux labels -- we don't want to relabel the llama-stack source dir
   CLI_ARGS+=("--security-opt" "label=disable")
 fi