Dexopt flag tweax

v3:      v=n,o=v,u=n,m=y
default: v=a,o=v
therefore, aosp's m=y is really:
         v=a,o=v,    m=y

going to drop the u

Change-Id: Ie96f64453a8d9d2f460c6b1da33a4c5e1a5655cc