Correct ActivityInfo constructors.

ActivityInfo was missing initialization for the
documentLaunchMode flag in the copy-constructor
and the Parcel constructor. The copy-constructor
is used in multi-user/profile mode to create a
seperate instance of the ActivityInfo per uid
and this was manifesting in the linked bug.

Bug: 21590916
Change-Id: I6f71d94ec32ec6326d23c9b62e9d8d319e2fa25e
(cherry picked from commit 3e2e0117)