Harmonisation of GSC gain

Basic info

• Float reference:
  • Encoder (float):
  • Decoder (float):
• Fixed point:
  • Encoder (fixed): a0051869
  • Decoder (fixed): a0051869

Bug description

With some minimal adjustment, the same code can be used to (un)quantized the gain in GSC for both EVS and IVAS.

Will not always be BE for IVAS because of some difference in rounding, but quality will not be impacted

Ways to reproduce

Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-xxxx