Compile android.test.*.stubs into dex

Adjust the build rules of android.test.*.stubs packages to also
produce a jar with dex files. This will be used by the `hiddenapi`
tool to categorize the boot class path equivalents as public API.

Bug: 79409988
Test: m android.test.base.stubs ; check javalib.jar contains dex
Change-Id: I1d0850b18044c559ea4b9893d929dc45884b32c3

test-base/Android.bp

@@ -115,4 +115,5 @@ java_library_static {
         },
     },
     sdk_version: "current",
+    compile_dex: true,
 }