SF: Cleanup creating / destroying virtual display APIs

Follow-up CL for cleanup requested by SF owner in http://ag/27202517.

Misc:
- Fix type conversion warnings for print format.
- Return status destroying virtual display in SF and add appropriate
checks in UT.
- Use static constexpr / const for compile-time effciciency.

Bug: 339525838
Bug: 137375833
Bug: 194863377
Test: atest libsurfaceflinger_unittest
Test: atest SurfaceFlinger_test
Flag: EXEMPT refactor
Change-Id: I7859720989c9244b26f8764c3323a8495064c888
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index eee4fb9..6c6a849 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -673,13 +673,14 @@
         return binder::Status::ok();
     }
 
-    binder::Status createDisplay(const std::string& /*displayName*/, bool /*isSecure*/,
-                                 const std::string& /*uniqueId*/, float /*requestedRefreshRate*/,
-                                 sp<IBinder>* /*outDisplay*/) override {
+    binder::Status createVirtualDisplay(const std::string& /*displayName*/, bool /*isSecure*/,
+                                        const std::string& /*uniqueId*/,
+                                        float /*requestedRefreshRate*/,
+                                        sp<IBinder>* /*outDisplay*/) override {
         return binder::Status::ok();
     }
 
-    binder::Status destroyDisplay(const sp<IBinder>& /*display*/) override {
+    binder::Status destroyVirtualDisplay(const sp<IBinder>& /*displayToken*/) override {
         return binder::Status::ok();
     }