Update interface quota limit when network stats updated

In previous design, interface quota limit does not changed
when network stats are updated. However, this is incorrect
today since there are some offloaded traffic that cannot
be seen by kernel. If the limit is not updated, the offloaded
traffic might still be able to use whole quota as if there is
no embedded traffic.

This change also removes the re-arm global alert after
advising persist threshold if not changed, given that it will
cause an additional alert while updating interface quota limit.

Bug: 145792619
Test: 1. atest NetworkStatsServiceTest
      2. atest NetworkPolicyManagerServiceTest
      3. manual test: run speedtest, check dumpsys netd

Change-Id: I8d2203e713730d536430a234b1aa8b2468badee3