There is no way to recover when AGL postinstall failed

The conditional branch in exec_postinst_scriptlets() is strange. It cannot handle error from the script of installation for each application because it never watch return status of the script.

This is why run-agl-postinsts usually succeed even when some app fails to install.

This causes there is no way to recover when this script failed because this script remove all scripts to install each applications when there is no error (usually no error).