Avoid hiddenapi ignoring prebuilt with missing dex implementation jar

Previously, when a prebuilt was preferred but did not provide a
suitable boot dex jar both the source and the prebuilt were silently
ignored which meant that the "hiddenapi list" command was not given a
complete set of boot dex jars. That could either lead to incorrect
hiddenapi flags being set or the "hiddenapi list" command failing if it
could not find a class. Debugging the cause of either of those cases
can be very time consuming so this change fails early and makes the
cause very explicit.

Bug: 181267622
Test: m nothing
Change-Id: I6763ddb9ba90ed2e501d0cf7984f6655237e905d

java/java_test.go

@@ -114,20 +114,26 @@ func testJavaErrorWithConfig(t *testing.T, pattern string, config android.Config
 	pathCtx := android.PathContextForTesting(config)
 	dexpreopt.SetTestGlobalConfig(config, dexpreopt.GlobalConfigForTests(pathCtx))
 
+	runWithErrors(t, ctx, config, pattern)
+
+	return ctx, config
+}
+
+func runWithErrors(t *testing.T, ctx *android.TestContext, config android.Config, pattern string) {
 	ctx.Register()
 	_, errs := ctx.ParseBlueprintsFiles("Android.bp")
 	if len(errs) > 0 {
 		android.FailIfNoMatchingErrors(t, pattern, errs)
-		return ctx, config
+		return
 	}
 	_, errs = ctx.PrepareBuildActions(config)
 	if len(errs) > 0 {
 		android.FailIfNoMatchingErrors(t, pattern, errs)
-		return ctx, config
+		return
 	}
 
 	t.Fatalf("missing expected error %q (0 errors are returned)", pattern)
-	return ctx, config
+	return
 }
 
 func testJavaWithFS(t *testing.T, bp string, fs map[string][]byte) (*android.TestContext, android.Config) {