SDK Repository: switch to sdk addon revision 6. DO NOT MERGE.

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
(cherry picked from commit 7657a590830cfe87fb2dc6ff03c0dcb7589c0bdf)
1 file changed