[Large Screen] Fix deep link 2 tasks bug

When launching a Settings deep link, it will close
Activity of the deep link and start both
DeepLinkHomepageActivity & the deep link.

Since 1st launched deep link page is finished,
should also remove its task.

Bug: 203385355
Test: manual
      1. Create a Settings shortcut on launcher.
      2. Click the shortcut.
      3. Move Activity of the shortcut to background.
Change-Id: I04b3243bf51f3940167e4dca6f5a32d9e3cf2841