Obs YAMLs for SOCA are hard-coded for "gdas"

[CatherineThomas-NOAA]

When running WCDA with gfs_cyc/=0, the gfsprepoceanobs task creates obs with the prefix gdas. instead of gfs.. A look at one of the YAML files confirms that the output files are hardcoded for gdas. For example, sst_avhrr_mb_l3u2ioda.yaml:

name: sst_avhrr_mb_l3u
provider: GHRSST
dmpdir subdir: ocean/sst
output file: gdas.t18z.sst_avhrr_mb_l3u.2021032418.nc4

The gfsprepoceanobs job succeeds but the gfsocnanalrun fails.

@guillaumevernieres @AndrewEichmann-NOAA @ShastriPaturi @JessicaMeixner-NOAA

[ShastriPaturi]

@CatherineThomas-NOAA, yes it is an issue in the run prepoceanobs script especially for the netCDF files, the output file is hardcoded for gdas. I will try for a fix in my PR #914.