Update the version of the Android build tools to 26.0.2.
Update the version of the Android build tools to 26.0.2.

As of version 3.0.1, the Android plugin no longer supports any version of
the build tools under 26.0.2. This can create build issues if the library
is used as a submodule within a larger project. To keep everything
compatible, update the tool version.

jayschwa/AndroidSliderPreference