Fix run-tests.sh to accept multiple devices in ANDROID_SERIAL

Previously run-tests.sh observes ANDROID_SERIAL, or run tests on
ALL devices detected online (with proper abi/abi2) if ANDROID_SERIAL
is absent.  ANDROID_SERIAL is treated by fastboot/adb to contain
single device, though.

This CL fix run-tests.sh to allow ANDROID_SERIAL to carry multiple devices
(comma-delimited) for testing (instead of all detected)

Change-Id: I18d5a26f1dce9aae0a95618554b9b3990133e9a0
2 files changed