MobileDataStatsPuller: add rate limit before post msg to handler

Flag: com.android.server.stats.add_mobile_bytes_transfer_by_proc_state_puller
Bug: 387017693
Bug: 388200909
Test: manual trace collection & inspection
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:fa2bca4e3aa20b025d332dce982ac42ea85ca858)
Merged-In: Ibc740e91e75c7229960e7f32b0a089dc52fc8b80
Change-Id: Ibc740e91e75c7229960e7f32b0a089dc52fc8b80