pm: Add persist property to enable lazy dexopt

 * Add "persist.sys.lazy.dexopt" property to enable lazy dexopt
   on userdebug builds.  As much as I enjoy these 20 minute
   dexopt sessions, I prefer instant gratification.

Change-Id: I568692f04d67c3c0a1a138fb724eda41e24b1235
Merge branch 'cm-12.0' of https://github.com/CyanogenMod/android_frameworks_base into cm-12.0