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/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 7aaaebb..0a85cf8 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -1280,18 +1280,22 @@
 }
 // ---------------------------------------------------------------------------
 
-sp<IBinder> SurfaceComposerClient::createDisplay(const String8& displayName, bool isSecure,
-                                                 const std::string& uniqueId,
-                                                 float requestedRefreshRate) {
+sp<IBinder> SurfaceComposerClient::createVirtualDisplay(const std::string& displayName,
+                                                        bool isSecure, const std::string& uniqueId,
+                                                        float requestedRefreshRate) {
     sp<IBinder> display = nullptr;
-    binder::Status status = ComposerServiceAIDL::getComposerService()
-                                    ->createDisplay(std::string(displayName.c_str()), isSecure,
-                                                    uniqueId, requestedRefreshRate, &display);
+    binder::Status status =
+            ComposerServiceAIDL::getComposerService()->createVirtualDisplay(displayName, isSecure,
+                                                                            uniqueId,
+                                                                            requestedRefreshRate,
+                                                                            &display);
     return status.isOk() ? display : nullptr;
 }
 
-void SurfaceComposerClient::destroyDisplay(const sp<IBinder>& display) {
-    ComposerServiceAIDL::getComposerService()->destroyDisplay(display);
+status_t SurfaceComposerClient::destroyVirtualDisplay(const sp<IBinder>& displayToken) {
+    return ComposerServiceAIDL::getComposerService()
+            ->destroyVirtualDisplay(displayToken)
+            .transactionError();
 }
 
 std::vector<PhysicalDisplayId> SurfaceComposerClient::getPhysicalDisplayIds() {