Make sure background/shutdown threads are in AGENT_THREAD_GROUP (#8217)

Author: mcculls

dd-java-agent/agent-crashtracking/src/main/java/com/datadog/crashtracking/ScriptInitializer.java

@@ -1,5 +1,6 @@
 package com.datadog.crashtracking;
 
+import static datadog.trace.util.AgentThreadFactory.AGENT_THREAD_GROUP;
 import static java.util.Comparator.reverseOrder;
 import static java.util.Locale.ROOT;
 
@@ -92,6 +93,7 @@ static void writeConfig(Path scriptPath, String... entries) {
       Runtime.getRuntime()
           .addShutdownHook(
               new Thread(
+                  AGENT_THREAD_GROUP,
                   () -> {
                     try {
                       LOG.debug("Deleting config file: {}", cfgPath);

dd-java-agent/agent-profiling/profiling-controller/src/main/java/com/datadog/profiling/controller/TempLocationManager.java

@@ -1,6 +1,7 @@
 package com.datadog.profiling.controller;
 
 import static datadog.trace.api.telemetry.LogCollector.SEND_TELEMETRY;
+import static datadog.trace.util.AgentThreadFactory.AGENT_THREAD_GROUP;
 
 import datadog.trace.api.config.ProfilingConfig;
 import datadog.trace.bootstrap.config.provider.ConfigProvider;
@@ -297,6 +298,7 @@ private TempLocationManager() {
 
     Thread selfCleanup =
         new Thread(
+            AGENT_THREAD_GROUP,
             () -> {
               if (!waitForCleanup(1, TimeUnit.SECONDS)) {
                 log.info(