Increase time buffer to reduce flakiness in filter age test

Added a larger time buffer to the filter age difference check in
testFilterAgeIncreasesBetweenPackets to mitigate potential flakiness
caused by delays in the second ping reply.

Bug: 347641209
Test: TH
(cherry picked from https://android-review.googlesource.com/q/commit:89cafef056429b08f83ae36aab9aa1adb0c6be11)
Merged-In: I1a7698297bf36a295b1428c92bf83158539bb867
Change-Id: I1a7698297bf36a295b1428c92bf83158539bb867
1 file changed