tests: check if page scrubbing is still enabled when switching kernel
tests: check if page scrubbing is still enabled when switching kernel

QubesOS/qubes-issues#4736

marmarek/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin