ui: Pull DisplayMap.h from SF

...so it can be used in more places, e.g. libscheduler headers.

Clean up the verbose type for the frontend::DisplayInfo map by aliasing
it as frontend::DisplayInfos.

Bug: 241285475
Fixes: 256881188
Test: Build
Change-Id: Idf36e20ca304190e43618a6cfd7c67e8f62e9d40
diff --git a/services/surfaceflinger/tests/unittests/LayerSnapshotTest.cpp b/services/surfaceflinger/tests/unittests/LayerSnapshotTest.cpp
index b8a7446..12cf070 100644
--- a/services/surfaceflinger/tests/unittests/LayerSnapshotTest.cpp
+++ b/services/surfaceflinger/tests/unittests/LayerSnapshotTest.cpp
@@ -105,7 +105,7 @@
 
     LayerHierarchyBuilder mHierarchyBuilder{{}};
     LayerSnapshotBuilder mSnapshotBuilder;
-    display::DisplayMap<ui::LayerStack, frontend::DisplayInfo> mFrontEndDisplayInfos;
+    DisplayInfos mFrontEndDisplayInfos;
     renderengine::ShadowSettings globalShadowSettings;
     static const std::vector<uint32_t> STARTING_ZORDER;
 };