Init some time Process stats with very negative numbers

mLastTopTime was initialized as 0, meaning early on in the boot
OomAdjuster would mistakenly think apps had recently been in the TOP
state.

Also, changed mLastProviderTime even though it had some logic (now
removed) to avoid the mistake.

Test: atest MockingOomAdjustertest (ideally immediatly after boot)
Fixes: 300106850
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:1e35d99e4a8c394fc8ea11c8e4ed797c85a2e769)
Merged-In: I399d34e1a9a19b7211413e51099721ea49efa7ad
Change-Id: I399d34e1a9a19b7211413e51099721ea49efa7ad