Don't check for td-agent when installing without fluentd (#394)

internal/buildscripts/packaging/installer/install.ps1

@@ -336,11 +336,11 @@ if (service_installed -name "$service_name") {
     throw "The $service_name service is already installed. Remove/Uninstall the collector and re-run this script."
 }
 
-if (service_installed -name "$fluentd_service_name") {
+if ($with_fluentd -And (service_installed -name "$fluentd_service_name")) {
     throw "The $fluentd_service_name service is already installed. Remove/Uninstall fluentd and re-run this script."
 }
 
-if (Test-Path -Path "$fluentd_base_dir\bin\fluentd") {
+if ($with_fluentd -And (Test-Path -Path "$fluentd_base_dir\bin\fluentd")) {
     throw "$fluentd_base_dir\bin\fluentd is already installed. Remove/Uninstall fluentd and re-run this script."
 }
 

internal/buildscripts/packaging/installer/install.sh

@@ -274,7 +274,14 @@ install_yum_package() {
 }
 
 ensure_not_installed() {
-  for agent in otelcol td-agent; do
+  local with_fluentd="$1"
+  local agents="otelcol"
+
+  if [ "$with_fluentd" = "true" ]; then
+    agents="$agents td-agent"
+  fi
+
+  for agent in $agents; do
     if command -v $agent >/dev/null 2>&1; then
       echo "An agent binary already exists at $( command -v $agent ) which implies that the agent has already been installed." >&2
       echo "Please uninstall the agent and re-run this script." >&2
@@ -658,7 +665,7 @@ parse_args_and_install() {
       exit 0
   fi
 
-  ensure_not_installed
+  ensure_not_installed "$with_fluentd"
 
   if [ -z "$access_token" ]; then
     access_token=$(request_access_token)