Avoid double resource compilation

SystemUI resources are already compiled and included via "SystemUI-res".
resource_dirs defaults to "res", so the resources were being compiled
twice.

Bug: 307607958
Flag: EXEMPT build change is a no-op
Test: Build and flash device
Change-Id: I4fbe99dae629c7f2e5d4a201e68f1762dd55ceea
diff --git a/packages/SystemUI/Android.bp b/packages/SystemUI/Android.bp
index 5f90b39..60f5ad9 100644
--- a/packages/SystemUI/Android.bp
+++ b/packages/SystemUI/Android.bp
@@ -499,6 +499,7 @@
         },
     },
     use_resource_processor: true,
+    resource_dirs: [],
     static_libs: [
         "//frameworks/libs/systemui:compilelib",
         "SystemUI-res",