Add touch event of on taskbar for various cases

- Temporarily disable leak detection on tablets until b/191449914 is resolved
- Add touch event on taskbar when interacting with navigation buttons
- Added TaplTestsLauncher3.initialize to StartLauncherViaGestureTests which is present in TaplTestQuickstep to solve LauncherInstrumentation being null problem on tablets

Bug: 191344757, 191449914
Test: TaplTestQuickstep and StartLauncherViaGestureTests
Change-Id: I49accc458d133717f290140abe80aae8a683f6c0