Resolve "Split rendering without head tracking"

• Related issues: ivas-codec-pc/ivas-codec#1456 (closed), ivas-codec-pc/ivas-codec#1224
• Requested reviewers: @tyagiri

Reason why this change is needed

The IVAS decoder sets hDecoderConfig->Opt_Headrotation = 1 when split-rendering output format is requested but no head-tracking input file is provided via the cmd-line option -T command-line option and also no render config file is provided via the -render_config command-line option.

Related to

Description of the change

The IVAS decoder should default to 0DoF and no head-pose correction when no head-tracking input file is provided via the cmd-line option -T command-line option and at the same time no render config file is provided via the -render_config command-line option.

Affected operating points

No impact in our tests. The fix only affects very specific command-line conditions.