I was able to install the sap package manually and unlike my previous post, I managed to reproduce it several times.
Here is the procedure :
Copy packages from the host computer to the target. > sdb push [tizen_sdk_path]\platforms\tizen-4.0\wearable\emulator-images\add-ons\sap /tmp/.emulator/apps/sap
Switches to root mode > sdb root on
Remount filesystem as Read/Write > sdb shell mount -o rw,remount /
Install sap > sdb shell rpm -Uvh /tmp/.emulator/apps/sap/sap-1.9.5-0.i686.rpm
The package has been successfully installed. After emulator reboot, AccessoryService Emulator on Android Device was correctly connected.
I have reset the emulator several times and have repeated these operations, always successfully.
The error message (Extra package installation is failed…) still appears at startup, but the package is correctly installed and working.