updated getter for encryptionContext to be contentMetadata.encryptedDataKeyMatDescOrContext()

Author: Anirav Kareddy

src/main/java/software/amazon/encryption/s3/internal/GetEncryptedObjectPipeline.java

@@ -85,7 +85,7 @@ private DecryptionMaterials prepareMaterialsFromRequest(final GetObjectRequest g
                 .s3Request(getObjectRequest)
                 .algorithmSuite(algorithmSuite)
                 .encryptedDataKeys(encryptedDataKeys)
-                .encryptionContext(contentMetadata.encryptedDataKeyContext())
+                .encryptionContext(contentMetadata.encryptedDataKeyMatDescOrContext())
                 .ciphertextLength(getObjectResponse.contentLength())
                 .contentRange(getObjectRequest.range())
                 .build();