Reland of Generate Android .isolate files used for test()s

Now uses gen.runtime rather than gen to be included by
builder/tester configurations.

TBR=sgurun@chromium.org,vollick@chromium.org,dpranke@chromium.org,jochen@chromium.org,agrieve@chromium.org
NOTRY=true
BUG=589318

Review URL: https://codereview.chromium.org/1914573002

Cr-Commit-Position: refs/heads/master@{#389148}
8 files changed