On-The-Go: make it multiuser aware

Change-Id: Ib61cc35b196ead75dbd80b9b4bf2473df2ba444b

Conflicts:
	packages/SystemUI/src/com/android/systemui/nameless/onthego/OnTheGoDialog.java
	packages/SystemUI/src/com/android/systemui/nameless/onthego/OnTheGoService.java
Bring DownloadManager API inline with AOSPA

Change-Id: I9468e59617e2e6fd01a622c1c499ee52a096d291