feat(java/S3Uploads.java): use more generic terms when dealing with signatures
feat(java/S3Uploads.java): use more generic terms when dealing with signatures

paul-herrmann/server-examples,FineUploader/server-examples,FineUploader/server-examples,FineUploader/server-examples,FineUploader/server-examples,FineUploader/server-examples,paul-herrmann/server-examples,paul-herrmann/server-examples,paul-herrmann/server-examples,FineUploader/server-examples,paul-herrmann/server-examples,paul-herrmann/server-examples,paul-herrmann/server-examples,paul-herrmann/server-examples,FineUploader/server-examples,FineUploader/server-examples