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>
GC: Improve the string parsing for GC parameter setting

Improve the string parsing for GC parameter system property.
Previously we only recoganize plain number for dalvik.vm.heapminfree
and dalvik.vm.heapconcurrentstart, while users tend to use format as
2m.  Improve the string parse to cover such cases.

Change-Id: Iaf0152bc4d77e1caabc307a9a7b0e5b261f8e441