Bug fix for time labeling in GRIB2 template 4.46

[EricJames-NOAA]

This PR fixes the bug in time labeling for the RRFS 1-h average PM2.5 and PM10 variables. The code was tested for the RRFS_NA_3km system on Jet.

[WenMeng-NOAA]

@EricJames-NOAA Thanks for catching and fixing bugs in RRFS products.
I have run the UPP standalone test with RRFS NA model history files at /home/Wen.Meng/stmp2/rrfs_2022022412-after on Hera.
There are the following updates in PRSLEV data set:

From
  751:4804768430:d=2022022412:MASSDEN:8 m above ground:10-11 hour ave fcst:aerosol=Missing:aerosol_size <2.5e-06
  752:4807749213:d=2022022412:MASSDEN:8 m above ground:10-11 hour ave fcst:aerosol=Missing:aerosol_size <1e-05
Into
  751:4804768430:d=2022022412:MASSDEN:8 m above ground:9-10 hour ave fcst:aerosol=Total aerosol:aerosol_size <2.5e-06
  752:4807749213:d=2022022412:MASSDEN:8 m above ground:9-10 hour ave fcst:aerosol=Total aerosol:aerosol_size <1e-05

Please let me know if you see issues in my test.

[EricJames-NOAA]

@WenMeng-NOAA your test looks good to me! Thank you!

[WenMeng-NOAA]

This PR is ready for merging.