Some build.gradle features aren't available for Android modules

Today I tried to merge a Java project into an Android module so that a Gradle plugin could act on the entire codebase at once. I found that many features are provided by the Java plugin for Gradle (apply plugin: 'java') but not the Android plugin (apply plugin: 'com.android.application'). Unfortunately, those two plugins cannot be applied at the same time. It looks like I'll need to rewrite the custom plugin to work with the Android project.