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
1 file changed