Add mb_config.pyl entry for Android Debug (Nexus 5X).
Add mb_config.pyl entry for Android Debug (Nexus 5X).

BUG=591449
NOTRY=true

Review-Url: https://codereview.chromium.org/1950873002
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#391419}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk