Optimize code on get UidDetail in AppDataUsage

Optimize code on get UidDetail in AppDataUsage

The class UidDetailProvider providers details about a specific UID，
we can directly  apply it here.

Optimize: https://code.google.com/p/android/issues/detail?id=237810
Test: for case TrafficStats.UID_REMOVED
1.add an new User
2.generate some data traffic under the new user
3.switch to the phone owner
4.delete the User added just now
5.go to Data usage and open the item "Removed apps and users"

    for case TrafficStats.UID_TETHERING
1.open tethering and generate some data traffic
2.go to Data usage and open the item "Tethering & portable hotspot"

Change-Id: I05aa522728b296d6c06580adf809f274491cdcea
Signed-off-by: tiansiming <tiansiming@xiaomi.com>