This is a prerequisite for having them live within APK splits.
Although pak files need to be renamed to be stored under res/raw,
ResourceExtractor restores their original name during extraction (so no
change to native code).
All sub-locales are stored and extracted together, just as before.
BUG=371610
Review URL: https://codereview.chromium.org/1158053005
Cr-Original-Commit-Position: refs/heads/master@{#335350}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: f30e04470453ccd7e6a9abf586185b991d174902