Change SQL to improve performance.

To know the number of images, use "COUNT(*)" instead of "_id" in SQL.
Using "_id" gets all result set. and when getCount() is called, CursorWindow is filled.
But using "COUNT(*)" gets just 1by1 data.
So using "COUNT(*)" is more faster than now.
And this SQL is called everytime per a file during a file transfer in MTP
The better way is by using "EXIST".
But if using "EXIST", modify MediaProvider.call() method.
So i applied just a "COUNT(*)"

Change-Id: Ic5882af0fad2304f836b7b7043a4746359391609
Signed-off-by: muzbit.kim <muzbit.kim@lge.com>
Start MountService before performBootDexOpt

This change is to start Mountservice before starting
performBootDexOpt, as in one case, in performBootDexOpt
when system upgrade happens, StorageManager will be started to
get the low threshold of DataDir. But, at this point, as
Mountservice is still not up, StorageManager will end up
having a null object of Mountservice.

Change-Id: I6dec474266faa5de67449c1bbe6ef30791e5ecaa
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