fix(appsec): move BlockingException inside brf guard in all remaining paths

The content path in Netty and both the filenames and content paths in
Tomcat were setting the BlockingException outside the if (brf != null)
block, meaning the exception would be thrown even when no blocking
response had actually been committed. Align all three with the canonical
pattern: tryCommitBlockingResponse + effectivelyBlocked + exception
assignment all inside if (brf != null).

The Netty body-processed path intentionally still omits effectivelyBlocked()
because tryCommitBlockingResponse() closes the Netty span synchronously in
the test environment, making a subsequent effectivelyBlocked() call fail.

Author: jandro996

dd-java-agent/instrumentation/netty/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/HttpPostRequestDecoderInstrumentation.java

@@ -192,8 +192,8 @@ static void after(
           if (brf != null) {
             brf.tryCommitBlockingResponse(requestContext.getTraceSegment(), rba);
             requestContext.getTraceSegment().effectivelyBlocked();
+            thr = new BlockingException("Blocked request (multipart file upload content)");
           }
-          thr = new BlockingException("Blocked request (multipart file upload content)");
         }
       }
 

dd-java-agent/instrumentation/tomcat/tomcat-appsec/tomcat-appsec-7.0/src/main/java/datadog/trace/instrumentation/tomcat7/ParsePartsInstrumentation.java

@@ -143,8 +143,8 @@ static void after(
             if (brf != null) {
               brf.tryCommitBlockingResponse(reqCtx.getTraceSegment(), rba);
               reqCtx.getTraceSegment().effectivelyBlocked();
+              t = new BlockingException("Blocked request (multipart file upload)");
             }
-            t = new BlockingException("Blocked request (multipart file upload)");
           }
         }
       }
@@ -164,8 +164,8 @@ static void after(
               if (brf != null) {
                 brf.tryCommitBlockingResponse(reqCtx.getTraceSegment(), rba);
                 reqCtx.getTraceSegment().effectivelyBlocked();
+                t = new BlockingException("Blocked request (multipart file upload content)");
               }
-              t = new BlockingException("Blocked request (multipart file upload content)");
             }
           }
         }