Gradle

task appStart(type: Exec, dependsOn: ':installDebug') {
    // linux 
    commandLine 'adb', 'shell', 'am', 'start', '-n', 'com.example/.MyActivity'

    // windows
    // commandLine 'cmd', '/c', 'adb', 'shell', 'am', 'start', '-n', 'com.example/.MyActivity'      
}