Download: use "control" column to mark paused/resumed status

Before, column "status" is directly updated when user pauses/resumes
download, this causes status shown to user is not same as real status
because pausing/resuming needs a little time not instantly, and then
causes some status error.

The column "control" is updated instead of "status". When user pauses
download, will update "control" as CONTROL_PAUSED and set "status" as
STATUS_PAUSED_BY_APP until pausing operation is finished; and when
user resumes download, will update "control" as CONTROL_RUN and change
the status as STATUS_RUNNING until DownloadThread is started to run.
Then the status shown to user will be same with real download status.

Change-Id: I2204b972d24b809f7914b0981cad11e9175f4ae6
CRs-Fixed: 737182
Signed-off-by: Jake Weinstein <xboxlover360@gmail.com>
Framework/base: Relocating GC calls at the end of loop during zygote init

Relocating explicit GC calls at the end of the loop during the preloading
the resources and preloading clases, with this changes boottime improved.

Change-Id: I2e05ef68578eddca8cd435b5186e198ee7d71739
Signed-off-by: Jake Weinstein <xboxlover360@gmail.com>