run-test: add --external-log-tags options

Bug: 171770326
Test: art/test/run-test --host 001-HelloWorld
Test: ANDROID_LOG_TAGS="*:V" art/test/run-test --external-log-tags \
                                               --host 001-HelloWorld
Test: ANDROID_LOG_TAGS="*:E" art/test/run-test --external-log-tags \
                                               --host 001-HelloWorld
Change-Id: Ibe27047549fd7c3c556e2e754015a2cfaa97d6cf
1 file changed