Fixing the flickering issue when clock is clicked in status bar to open Quick Settings.

Adding the flag "Intent.FLAG_ACTIVITY_SINGLE_TOP" which will stop the activity to relaunch if its already there.

Bug: 121345477
Test: Manual
Change-Id: I83f985c83d4954a722591b59fc7f6db24a923923
(cherry picked from commit a9971e07144bfa7fde5f4ae2cd602efb8ff02fec)