Support launching activities in a new task for Injection.

Create a new meta data for clients to determine if an injected item
should be launched in a separate task.

Bug: 197702494
Bug: 197700978
Bug: 197702789
Test: Set this metadata to true and make sure this page is launched in
another task.

Change-Id: Iae6b1e8645aea9e6dc4c89684c12c40b67c852d1