Update Dual Boot Tool again

DERP:
i slight changed the original commit "Update dual boot tool" by @kumajaya wich
giot applyed before.
i changed to create a 1.5 GB dynamic growth sparse image instead 2.0 GB
because we don't need a bigger system.img on this device - but i forgot
to change the aromaconfig to display 1.5 instead 2.0 GB.

Change-Id: Iaacab2ab220fbb4775eaf341fd716e1d1d058692