Fix nobootanimation toggle

The sf.debug.nobootanimation was apparently broken in a recent
refactoring. Flipping the boolean in the utils fixes the issue.

Left some additional logging behind.

Test: marlin-eng boots
Test: my test can prevent the boot animation
Test: shell stop start shows boot animation
Change-Id: I815708a2f16a3a8688cf1a53695e5a8d43194575