Don't shade org.apache.log4j (#4827)

- This is not a direct dependency of the SDK, and no log4j classes are actually
   included in the bundle, so we should not be shading it.
 - By not shading it, classes that we *do* include in the bundle, i.e. from
   apache-commons-logging can reference the log4j classes properly.

.changes/next-release/bugfix-AWSSDKforJavav2-1e17bfe.json

@@ -0,0 +1,6 @@
+{
+    "type": "bugfix",
+    "category": "AWS SDK for Java v2",
+    "contributor": "",
+    "description": "Fix shading of artifacts in the `bundle` by not `org.apache.log4j.*` packages. This allows proper binding of `commons-logging` to Log4J and enables dependencies that use commons logging (e.g. Apache HTTP Client) to properly bind to Log4j."
+}

bundle-sdk/pom.xml

@@ -83,6 +83,9 @@
                             <relocation>
                                 <pattern>org.apache</pattern>
                                 <shadedPattern>software.amazon.awssdk.thirdparty.org.apache</shadedPattern>
+                                <excludes>
+                                    <exclude>org.apache.log4j.*</exclude>
+                                </excludes>
                             </relocation>
                             <relocation>
                                 <pattern>io.netty</pattern>