Apply multi_task flag with startIntents

The multi_task flag is not applied to the activityOption when start
shortcut to split. This CL update the activityOption with mult_task
flag while supporting multi-instances in split.

Bug: 291751952
Test: Start shortcuts with chrome into split
Change-Id: I71bfd39458927625143357baa5c1ed47eabcdfaf
1 file changed