Revert "Use new onTaskListUpdated() callback"

This reverts commit a04997b0811f2af79c0a91046d85d7e992496cab.

Reason for revert: Platform master has API changes, and launcher-master should still map to qpr branch

Change-Id: Ib201c71b5557715d585d322ec2a1a528e352e61c
3 files changed