Notes about how to use gradlew to generate applications :

• In cmd , type command to show the 'adb.exe' under 'SDK' folder , and connect testing device .

$ where adb.exe
C:\cmdtool\adb.exe
C:\Users\XXX\AppData\Local\Android\sdk\platform-tools\adb.exe
C:\Users\XXX\AppData\Local\Android\sdk\platform-tools\adb.exe connect %deviceIp%

• In git bash , change to the current working project directory , then :

./gradlew assemblDebug

./gradlew assembleDebugAndroidTest

If below message ever shows :

> SDK location not found. Define location with sdk.dir in the local.properties file or with an ANDROID_HOME environment variable.

In current working project directory , create file 'local.properties' , in which :

sdk.dir=C\:\\Users\\XXX\\AppData\\Local\\Android\\Sdk

Notice the number of the slash .
Then

./gradlew assemblDebug

./gradlew assembleDebugAndroidTest

After 'BUILD SUCCESSFUL' shows , you're likely to get your two applications in :

%current_project_directory%\app\build\outputs\apk\