Reduce unnecessary initialization of DisplayAdjustments

The configuration of default DisplayAdjustments is already EMPTY.
If there is no override configuration, it doesn't need to set
EMPTY to EMPTY again.

Bug: 436271385
Flag: EXEMPT refacor without logic change
Test: ResourcesManagerPerfTest#getResourcesCached
Change-Id: Ib4f7862c3f7005141308c9ef5f18c16289e26562