Move data stall definitions out from Setting

From mainline perspective, we should use android flag api
instead of using Settings. Thus, move the definitions into
NetworkStack.

Bug:120013793
Test: atest NetworkStackTests SettingsBackupTest
Change-Id: I8e1fb5b47fff3bf624131ba1f5732daabd991e6d
Merged-In: I8e1fb5b47fff3bf624131ba1f5732daabd991e6d
Merged-In: I0a2a1e5d3de14ea86556ca471e26064df3481412
4 files changed