Revert "debug: allow ability to hide GC freed lines in logcat"

This reverts commit e1acf1d2e2539423b5edd2366648c799245c535b.
Removed excessive GC freed lines instead disable them

CM has introduced a method to disable GC freed lines by setting dalvik.vm.debug.alloc to 0: http://review.cyanogenmod.org/#/c/45785/
Now I doubt whether this method is effective or even could make the dalvik performance worse than before.
This method checks the property dalvik.vm.debug.alloc and convert the property value from string to integer everytime before dalvik writes debug line to logcat.
It is probably better to let dalvik to do only one operation to write debug line rather than to do two operations:
* Looking a property from a map that could contains hundred of properties
* Converting property value from string to integer
Since Heap.cpp is not a class, we cannot have a member variable that holds the property value by reading the property only once.
I don't think I'll need these debug lines, therefore I decided to remove them together with other information that are used in the debug line.

Change-Id: I164584bc3f53e5471a2e194125a867fd244a5774