DownloadProvider: Transfer speeds in notification

Change-Id: Ic7efcdfe7a329946f3b63c331064ac2f16faafeb
merge changes from Omni 4.4 into local branch

Conflicts:
	src/com/android/providers/downloads/DownloadNotifier.java

Change-Id: I23e194d54de15c5fb56aad7058a8cb1ebf0020aa