Null check for clientOverrideConfiguration

Author: davidh44

core/sdk-core/src/main/java/software/amazon/awssdk/core/client/builder/SdkDefaultClientBuilder.java

@@ -329,13 +329,16 @@ private RequestCompressionConfiguration resolveRequestCompressionConfiguration()
         Integer minCompressionThreshold = null;
 
         // Client level
-        RequestCompressionConfiguration clientConfig =
-            clientOverrideConfiguration.requestCompressionConfiguration().orElse(null);
-        if (clientConfig != null) {
-            requestCompressionEnabled = clientConfig.requestCompressionEnabled();
-            minCompressionThreshold = clientConfig.minimumCompressionThresholdInBytes();
+        if (clientOverrideConfiguration != null) {
+            RequestCompressionConfiguration clientConfig =
+                clientOverrideConfiguration.requestCompressionConfiguration().orElse(null);
+            if (clientConfig != null) {
+                requestCompressionEnabled = clientConfig.requestCompressionEnabled();
+                minCompressionThreshold = clientConfig.minimumCompressionThresholdInBytes();
+            }
         }
 
+
         // Env level
         if (requestCompressionEnabled == null) {
             Optional<Boolean> systemSetting = SdkSystemSetting.AWS_DISABLE_REQUEST_COMPRESSION.getBooleanValue();