Fix stem to be propagated to output jar name in java_library

Currently, java_library.stem property is not correctly reflected in the
output jar name in java_library when the module specifies
java_resource_dirs property. This change fixes the unexpected behavior
so that setting the stem property behaves as expected.

Test: go test ./java && m
Bug: 285843207
Change-Id: I0941fcea83c92f4c42ae415aa6ad9125da5cf57b

java/java_test.go

@@ -2351,3 +2351,22 @@ func TestJavaExcludeStaticLib(t *testing.T) {
 		`stable.core.platform.api.stubs`,
 	})
 }
+
+func TestJavaLibraryWithResourcesStem(t *testing.T) {
+	ctx, _ := testJavaWithFS(t, `
+    java_library {
+        name: "foo",
+        java_resource_dirs: ["test-jar"],
+        stem: "test",
+    }
+    `,
+		map[string][]byte{
+			"test-jar/test/resource.txt": nil,
+		})
+
+	m := ctx.ModuleForTests("foo", "android_common")
+	outputs := fmt.Sprint(m.AllOutputs())
+	if !strings.Contains(outputs, "test.jar") {
+		t.Errorf("Module output does not contain expected jar %s", "test.jar")
+	}
+}