Add dependency from hostdex installed module to Make intermediates

The art tests rely on a dependency existing from
out/host/linux-x86/framework/core-oj-hostdex.jar to
out/host/common/obj/JAVA_LIBRARIES/core-oj-hostdex_intermediates/classes.jar,
override LOCAL_SOONG_INSTALLED_MODULE for the hostdex modules so that
soong_java_prebuilt.mk adds the dependency.

Test: art/tools/buildbot-build.sh --host && art/tools/run-libcore-tests.sh '--mode=host' '--variant=X64' --debug
Change-Id: I9412147fc66d5e5f0dae52d522868a37251f781e
diff --git a/java/base.go b/java/base.go
index 859baaf..6930bcd 100644
--- a/java/base.go
+++ b/java/base.go
@@ -407,6 +407,9 @@
 	// installed file for binary dependency
 	installFile android.Path
 
+	// installed file for hostdex copy
+	hostdexInstallFile android.InstallPath
+
 	// list of .java files and srcjars that was passed to javac
 	compiledJavaSrcs android.Paths
 	compiledSrcJars  android.Paths