Do not append deps to exports when java_library has only proto srcs

This is to address the comment in aosp/2748099

Test: CI

Bug: 285952385
Change-Id: I0bc8c76e2bc9ee113ced8642e0ab93a95799211c
diff --git a/java/java.go b/java/java.go
index 270f456..3567dbe 100644
--- a/java/java.go
+++ b/java/java.go
@@ -3143,9 +3143,7 @@
 			// bp2build converts this module to 2 java_libraries + java_xx_proto_library + proto_library
 			// the non-empty deps here are not necessary for compiling the protos, in which case
 			// they're unnecessary as deps on the java_library as well since they aren't
-			// being propagated to any dependencies.
-			// so we can put the deps to exports and drop deps here.
-			exports.Append(deps)
+			// being propagated to any dependencies. So we can drop deps here.
 			deps = bazel.LabelListAttribute{}
 		} else {
 			ctx.ModuleErrorf("Module has direct dependencies but no sources. Bazel will not allow this.")