awss3sink: Add properties to set content-Type and content-disposition.
requested to merge rajneeshksoni/gst-plugins-rs:s3sink-set-content-type-and-disposition-headers into main
for uploaded object default content-type is set to binary/octet-stream, which is correct. metadata cannot be used to set content-type and content-disposition as setting metadata add a prefix x-amz-meta to key e.g. setting metadate "content-type=video/mp4" actually set value as x-amz-meta-content-type. So these has to be seaprate property.