Avoid configuring JavaCompile tasks eagerly.

Fixes #120

Author: runningcode

src/main/groovy/org/gradle/android/workarounds/CompilerArgsProcessor.groovy

@@ -40,7 +40,7 @@ class CompilerArgsProcessor {
         }
         applied = true
 
-        project.tasks.withType(JavaCompile) { JavaCompile task ->
+        project.tasks.withType(JavaCompile).configureEach { JavaCompile task ->
             project.gradle.taskGraph.beforeTask {
                 if (task == it) {
                     def processedArgs = processArgs(task.options.compilerArgs, task)

src/test/groovy/org/gradle/android/TaskAvoidanceTest.groovy

@@ -0,0 +1,55 @@
+package org.gradle.android
+
+import org.gradle.util.GradleVersion
+import org.gradle.util.VersionNumber
+import spock.lang.Unroll
+
+class TaskAvoidanceTest extends AbstractTest {
+    @Unroll
+    def "tasks are avoided with #gradleVersion and Android plugin #androidVersion"() {
+        assert gradleVersion instanceof GradleVersion
+        assert androidVersion instanceof VersionNumber
+
+        println "> Using Android plugin $androidVersion"
+        println "> Running with $gradleVersion"
+
+        SimpleAndroidApp.builder(temporaryFolder.root, cacheDir)
+                .withAndroidVersion(androidVersion)
+        .withKotlinDisabled()
+                .build()
+                .writeProject()
+
+        def originalSettings = file('build.gradle').text
+        file('build.gradle').text = """
+            ${originalSettings}
+
+            allprojects {
+              tasks.configureEach {
+                println "configuring \$it"
+              }
+            }
+        """
+
+        when:
+        def result = withGradleVersion(gradleVersion.version)
+                .withProjectDir(temporaryFolder.root)
+                .withArguments("help")
+                .build()
+
+        then:
+        result.output.contains("configuring task ':help'")
+        !result.output.contains("configuring task ':app:compileDebugJavaWithJavac'")
+        !result.output.contains("configuring task ':app:compileDebugAndroidTestJavaWithJavac'")
+        !result.output.contains("configuring task ':app:compileDebugUnitTestJavaWithJavac'")
+        !result.output.contains("configuring task ':app:compileReleaseJavaWithJavac'")
+        !result.output.contains("configuring task ':app:compileReleaseUnitTestJavaWithJavac'")
+        !result.output.contains("configuring task ':library:compileDebugJavaWithJavac'")
+        !result.output.contains("configuring task ':library:compileDebugAndroidTestJavaWithJavac'")
+        !result.output.contains("configuring task ':library:compileDebugUnitTestJavaWithJavac'")
+        !result.output.contains("configuring task ':library:compileReleaseJavaWithJavac'")
+        !result.output.contains("configuring task ':library:compileReleaseUnitTestJavaWithJavac'")
+
+        where:
+        [androidVersion, gradleVersion] << Versions.SUPPORTED_VERSIONS_MATRIX.entries().collect { [it.key, it.value] }
+    }
+}