Change log message to avoid confusing about display config update

It is no harm because if there is no real changes, it is no-op.
And if there are config changes, performDisplayOverrideConfigUpdate
will call requestChangeTransition. So it shouldn't be an error log.

Bug: 163976519
Flag: EXEMPT LOG_ONLY
Test: presubmit
Change-Id: I21b02e62cd22fa51a35b7c27d509701a91bbcbfe