statically initialize ProfilingActivationListener in test

Author: jackshirazi

inferred-spans/src/test/java/io/opentelemetry/contrib/inferredspans/internal/SamplingProfilerTest.java

@@ -43,6 +43,10 @@
 @DisabledOnOpenJ9
 class SamplingProfilerTest {
 
+  static {
+    ProfilingActivationListener.ensureInitialized();
+  }
+
   private ProfilerTestSetup setup;
 
   @TempDir private Path tempDir;