am: Handle unchecked activity starts for protected components.

  Previously if you received a notification from a protected app,
  since AM would state that the calling package was also the target
  package, the protected apps implementation would allow you to
  launch into the application. Mitigate this by hooking into
  the unchecked activity start stack (pending intent launches)
  globally.

Change-Id: I0371593ade9e4af2554962873d89a0f82a639b57
TICKET: PAELLA-216 FEIJ-160 FEIJ-177
(cherry picked from commit b7583ae4)