SDK Repository: switch to sdk addon revision 6.

addon-6.xsd changes <extra><revision> from an int (major only)
to a full <revision> element with major.micro.minor (but not
preview part.)

Change-Id: Ia37e75a2c8f86f4ecf36edb218f7e243f66a0b36
support7demos: MenuItem.SHOW_AS_ACTION_IF_ROOM is API level 11, better use MenuItemCompat.SHOW_AS_ACTION_IF_ROOM

Change-Id: Ic6de80cde42ccb89cdaa373c0b2b0a33d5513116
Signed-off-by: Guillaume Cottenceau <gcottenc@gmail.com>