Update startup compilation thresholds

This change aims to compile less startup methods to save RAM and
reduce code size. Numbers are from shortly after launching the apps.

Leave cutoff as 1 for high end devices for now. We may want to
revisit that later.

For low ram devices, the cutoff is 256. This regresses startup time
by 1% but saves more RAM. Results:
(odex+vdex) PSS: -25% average
odex size: -42% average
vdex size unchanged
Apps: Gmail, Maps, YouTube, Search

Spreadsheet at go/compilethreshold

Bug: 36457259
Test: test-art-host
Change-Id: I49d157df9379532d8d7a1ea1d844bb4beb195bb2