Adding experimental option to target Java 11

Bug: 195387073
Test: m
Test: EXPERIMENTAL_TARGET_JAVA_VERSION_11=true m
Change-Id: Ifd7ce6218a2761a8eaf79af7d91210da2fa581aa
diff --git a/java/java.go b/java/java.go
index ee1fd8a..90a1b89 100644
--- a/java/java.go
+++ b/java/java.go
@@ -434,6 +434,12 @@
 		return normalizeJavaVersion(ctx, javaVersion)
 	} else if ctx.Device() {
 		return defaultJavaLanguageVersion(ctx, sdkContext.SdkVersion(ctx))
+	} else if ctx.Config().IsEnvTrue("EXPERIMENTAL_TARGET_JAVA_VERSION_11") {
+		// 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
+		// target an older version intact.
+		return JAVA_VERSION_11
 	} else {
 		return JAVA_VERSION_9
 	}