MASA pre-renderer not updating energy information in a specific case

MASA pre-renderer merges two MASA metadata streams. The exact method used by ivas_prerend_merge_masa_metadata depends from

• If one metadata stream is originating from an ISM input, and
• the number of directions in the metadata.

In the specific case of first input metadata originating from ISM (and the second one not originating from ISM), and both metadata streams having 1 direction, the energy after the merge is not updated. This is because the sub-routine diffuse_meta_merge_1x1 updates the energy to the first energy argument.