Add this define to the config used for mksnapshot. This fixes a bug
where certain applications would fail at runtime on Chromecast.

BUG=592660
LOG=Y
Bug: internal b/27495984

Test: Formerly broken Cast apps load and run as expected.

Review URL: https://codereview.chromium.org/1839763003

Cr-Commit-Position: refs/heads/master@{#35183}