Use TM SubId in getDataState and getDataActivity

-Update getDataState() API to use the SubId specified
 by the TelephonyManager instance.

-Update the getDataActivity() API to use the SubId
 specified by the TelephonyManager instance.

(This CL is an un-revert of aosp/984377)

Bug: 135205433
Test: manual (automated test is infeasible)
Change-Id: I035f2c44a7955e88608b1c336acb72fb68c3e450
Merged-In: I035f2c44a7955e88608b1c336acb72fb68c3e450