Use soong_zip -srcjar for proto and aidl srcjars

IntelliJ's indexer is unhappy with the full paths in the proto
and aidl srcjars.  Use the -srcjar argument to soong_zip, which
causes it to extract the correct filename for .java files based on
the package statement in the file.

Bug: 176209347
Test: manual
Change-Id: I63d9d4f6ba670e3b851835d719519d675ae54c7f
diff --git a/java/gen.go b/java/gen.go
index 5766a94..4f928d5 100644
--- a/java/gen.go
+++ b/java/gen.go
@@ -78,10 +78,7 @@
 
 		rule.Command().
 			Tool(ctx.Config().HostToolPath(ctx, "soong_zip")).
-			// TODO(b/124333557): this can't use -srcjar for now, aidl on parcelables generates java files
-			//  without a package statement, which causes -srcjar to put them in the top level of the zip file.
-			//  Once aidl skips parcelables we can use -srcjar.
-			//Flag("-srcjar").
+			Flag("-srcjar").
 			Flag("-write_if_changed").
 			FlagWithOutput("-o ", srcJarFile).
 			FlagWithArg("-C ", outDir.String()).