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/services/surfaceflinger/tests/VirtualDisplay_test.cpp b/services/surfaceflinger/tests/VirtualDisplay_test.cpp
index f31f582..cd66dd2 100644
--- a/services/surfaceflinger/tests/VirtualDisplay_test.cpp
+++ b/services/surfaceflinger/tests/VirtualDisplay_test.cpp
@@ -41,14 +41,15 @@
 };
 
 TEST_F(VirtualDisplayTest, VirtualDisplayDestroyedSurfaceReuse) {
+    static const std::string kDisplayName("VirtualDisplay");
     sp<IBinder> virtualDisplay =
-            SurfaceComposerClient::createDisplay(String8("VirtualDisplay"), false /*secure*/);
+            SurfaceComposerClient::createVirtualDisplay(kDisplayName, false /*isSecure*/);
 
     SurfaceComposerClient::Transaction t;
     t.setDisplaySurface(virtualDisplay, mProducer);
     t.apply(true);
 
-    SurfaceComposerClient::destroyDisplay(virtualDisplay);
+    EXPECT_EQ(NO_ERROR, SurfaceComposerClient::destroyVirtualDisplay(virtualDisplay));
     virtualDisplay.clear();
     // Sync here to ensure the display was completely destroyed in SF
     t.apply(true);