Adding option to include sources only for Java 11 builds

Bug: 207852002
Test: m
Test: EXPERIMENTAL_TARGET_JAVA_VERSION_11=true m
Change-Id: I554a79798ea7f1dd4a96b09f761090f83a009cb4
diff --git a/java/java.go b/java/java.go
index 35b5ec3..9b4a005 100644
--- a/java/java.go
+++ b/java/java.go
@@ -449,7 +449,7 @@
 		return normalizeJavaVersion(ctx, javaVersion)
 	} else if ctx.Device() {
 		return defaultJavaLanguageVersion(ctx, sdkContext.SdkVersion(ctx))
-	} else if ctx.Config().IsEnvTrue("EXPERIMENTAL_TARGET_JAVA_VERSION_11") {
+	} else if ctx.Config().TargetsJava11() {
 		// Temporary experimental flag to be able to try and build with
 		// java version 11 options.  The flag, if used, just sets Java
 		// 11 as the default version, leaving any components that