Ability to disable auto instrumentations (#3533)

Co-authored-by: Trask Stalnaker <trask.stalnaker@gmail.com>

Author: jeanbisutti

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/init/AiConfigCustomizer.java

@@ -135,6 +135,11 @@ public Map<String, String> apply(ConfigProperties otelConfig) {
 
   private static void enableInstrumentations(
       ConfigProperties otelConfig, Configuration config, Map<String, String> properties) {
+
+    if (otelConfig.getBoolean("applicationinsights.testing.instrumentation.disabled", false)) {
+      return;
+    }
+
     properties.put("otel.instrumentation.common.default-enabled", "false");
 
     properties.put("otel.instrumentation.experimental.span-suppression-strategy", "client");