This allows creating tests for AppRTC Android demo that will be run on the host machine instead of a device. These tests can mock Android APIs through Robolectric. Because the tests are run on the host machine, they run much faster. BUG=webrtc:5896 NOTRY=True Review-Url: https://codereview.webrtc.org/1985663002 Cr-Commit-Position: refs/heads/master@{#12769}