fix: use number format exception

Author: diegomarquezp

gax-java/gax/src/main/java/com/google/api/gax/tracing/SpanTracer.java

@@ -147,7 +147,11 @@ private long extractContentLength(final java.util.Map<String, Object> headers) {
     if (headers == null || headerGetter.get() == null) {
       return -1;
     }
-    return Long.parseLong(String.valueOf(headerGetter.get()));
+    try {
+      return Long.parseLong(String.valueOf(headerGetter.get()));
+    } catch (NumberFormatException ex) {
+      return -1;
+    }
   }
 
   private void endAttempt() {

gax-java/gax/src/test/java/com/google/api/gax/tracing/SpanTracerTest.java

@@ -117,9 +117,23 @@ void testResponseHeadersReceived_missingContentLength() {
     headers.put("Other-Header", "123");
     spanTracer.responseHeadersReceived(headers);
 
-    verify(span, org.mockito.Mockito.never())
-        .setAttribute(
-            org.mockito.ArgumentMatchers.eq(ObservabilityAttributes.HTTP_RESPONSE_BODY_SIZE),
-            org.mockito.ArgumentMatchers.anyLong());
-  }
+		verify(span, org.mockito.Mockito.never())
+				.setAttribute(
+						org.mockito.ArgumentMatchers.eq(ObservabilityAttributes.HTTP_RESPONSE_BODY_SIZE),
+						org.mockito.ArgumentMatchers.anyLong());
+	}
+
+	@Test
+	void testResponseHeadersReceived_badFormat() {
+		spanTracer.attemptStarted(new Object(), 1);
+
+		java.util.Map<String, Object> headers = new java.util.HashMap<>();
+		headers.put("Other-Header", "12X3");
+		spanTracer.responseHeadersReceived(headers);
+
+		verify(span, org.mockito.Mockito.never())
+				.setAttribute(
+						org.mockito.ArgumentMatchers.eq(ObservabilityAttributes.HTTP_RESPONSE_BODY_SIZE),
+						org.mockito.ArgumentMatchers.eq(-1));
+	}
 }