[Pod] Update systemui_core benchmark to modify CentralSurfacesImpl.

As part of the pods project, we're going to move the
SystemUIApplicationImpl class out of the SystemUI-core build target. So,
we need to update the systemui_core_add_log_call_benchmark to modify a
class that will still be in the SystemUI-core build target even after
SystemUIApplicationImpl is moved.

Checking locally, this benchmark returned virtually the same number when
modifying SystemUIApplicationImpl vs CentralSurfacesImpl (4m40s vs
4m39s), so I think this metric will be stable even with this change.

Bug: 307607958
Test: `build/make/tools/perf/benchmarks --benchmark
systemui_core_add_log_call` -> runs benchmark, returns approximately
same value as before

Change-Id: I69e0850d64e13d39a0bf46d51b802d69d59d7feb