Making enable_multidex on by default

This will prevent us from having to turn on enable_multidex = true every time we
hit a dex limit on some target.

TBR: blink
Bug: 917426
Change-Id: I551fb5020b7e4cde86ac59523f01f4edea9a3e71
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1518341
Commit-Queue: Sam Maier <smaier@chromium.org>
Reviewed-by: Changwan Ryu <changwan@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Auto-Submit: Sam Maier <smaier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642941}
12 files changed