fix parser + test for async-profiler 4.1

Author: SylvainJuge

inferred-spans/src/main/java/io/opentelemetry/contrib/inferredspans/internal/asyncprofiler/JfrParser.java

@@ -199,6 +199,10 @@ private void parseConstantPool() throws IOException {
       case ContentTypeId.CONTENT_SYMBOL:
         readSymbolConstants(count);
         break;
+      case ContentTypeId.CONTENT_STRING:
+        // ignore empty string
+        bufferedFile.skip(2);
+        break;
       default:
         throw new IllegalStateException("Unhandled constant pool type: " + typeId);
     }
@@ -499,5 +503,6 @@ private ContentTypeId() {}
     static final int CONTENT_FRAME_TYPE = 24;
     static final int CONTENT_GC_WHEN = 32;
     static final int CONTENT_PACKAGE = 30;
+    static final int CONTENT_STRING = 20;
   }
 }

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

@@ -58,6 +58,6 @@ void name() throws Exception {
           }
           stackFrames.clear();
         });
-    assertThat(stackTraces.get()).isEqualTo(66);
+    assertThat(stackTraces.get()).isEqualTo(92);
   }
 }