Don't pass static libs to r8

r8 gets the static libs in the program jar, it shouldn't also get
them as library jars.  Keep a separate classpath for dexing that
includes libs but not static_libs.

Bug: 222468116
Test: m checkbuild
Test: TestD8
Test: TestR8
Change-Id: Icca3393f496cbcadcc633f3b156761e6c145f975
diff --git a/java/Android.bp b/java/Android.bp
index c062941..4bcae4f 100644
--- a/java/Android.bp
+++ b/java/Android.bp
@@ -81,6 +81,7 @@
         "app_test.go",
         "bootclasspath_fragment_test.go",
         "device_host_converter_test.go",
+        "dex_test.go",
         "dexpreopt_test.go",
         "dexpreopt_bootjars_test.go",
         "droiddoc_test.go",