Multiple UAC1001 serialization warnings are thrown in the Console window when importing Standard Characters Sample

Steps to reproduce:
1. Create new Unity project
2. Install Character Controller package via Package Manager
3. Import Standard Characters Sample
4. Observe the Console window

Actual results: multiple UAC1001 serialization warnings are thrown in the Console after importing the Sample
Expected results: no warnings are thrown in the Console window after importing the Sample

Reproducible with versions: 6000.5.0a9 (253a859729df), 6000.5.0b4, 6000.6.0a2
Not reproducible with versions: 6000.4.3f1, 6000.5.0a8 (d36222f39966)

Tested on (OS): macOS Silicon Tahoe 26.4 (M1)