Gradle Android build SDK location not found

Building Android project needs the Android SDK, if you don't have it, you will get this error when import Gradle Android into Eclipse.

Support for clients using tooling API version 1.5 is deprecated and will be removed in Gradle 3.0. You should upgrade your tooling API client to version 2.0 or later.
WARNING: The `android.dexOptions.incremental` property is deprecated and it has no effect on the build process.
FAILURE: Build failed with an exception.
* What went wrong:
A problem occurred configuring project ':app'.
> SDK location not found. Define location with sdk.dir in the file or with an ANDROID_HOME environment variable.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
Total time: 33 mins 54.254 secs

The first step is install the Android SDK

Be patient, you may wait very long because the Android SDK is a huge package, the manager will download them one by one.

Now create a new file with name in root of the project and add the following line to it