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/sdk.go b/java/sdk.go
index de7070e..756a24d 100644
--- a/java/sdk.go
+++ b/java/sdk.go
@@ -55,7 +55,7 @@
 		return JAVA_VERSION_7
 	} else if sdk.FinalOrFutureInt() <= 29 {
 		return JAVA_VERSION_8
-	} 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