[macOS] Use consistent filenames for tests (flutter#37755)

Previously there were two conventions for test filenames in the macOS
embedder: some ended in Unittests.mm and others eneded in Test.mm. This
applies a consistent naming convention, which is also consistent with
the iOS and common Darwin tests. Stock C++ unittests should continue to
use the _unittests.cc convention.

Author: cbracken

ci/licenses_golden/licenses_flutter

@@ -2619,16 +2619,16 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterBacki
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterBackingStore.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterChannelKeyResponder.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterChannelKeyResponder.mm
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterChannelKeyResponderUnittests.mm
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterChannelKeyResponderTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositor.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositor.mm
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositorUnittests.mm
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositorTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterDartProject.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEmbedderExternalTextureUnittests.mm
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEmbedderExternalTextureTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEmbedderKeyResponder.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEmbedderKeyResponder.mm
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEmbedderKeyResponderUnittests.mm
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEmbedderKeyResponderTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEngineTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEngineTestUtils.h
@@ -2641,7 +2641,7 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterIOSur
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyPrimaryResponder.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyboardManager.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyboardManager.mm
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyboardManagerUnittests.mm
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyboardManagerTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyboardViewDelegate.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuPlugin.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuPlugin.mm
@@ -2682,7 +2682,7 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterViewC
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterViewController_Internal.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterViewEngineProvider.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterViewEngineProvider.mm
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterViewEngineProviderUnittests.mm
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterViewEngineProviderTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterViewProvider.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/KeyCodeMap.g.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/KeyCodeMap_Internal.h

shell/platform/darwin/macos/BUILD.gn

@@ -165,14 +165,14 @@ executable("flutter_desktop_darwin_unittests") {
 
   sources = [
     "framework/Source/AccessibilityBridgeMacTest.mm",
-    "framework/Source/FlutterChannelKeyResponderUnittests.mm",
-    "framework/Source/FlutterCompositorUnittests.mm",
-    "framework/Source/FlutterEmbedderExternalTextureUnittests.mm",
-    "framework/Source/FlutterEmbedderKeyResponderUnittests.mm",
+    "framework/Source/FlutterChannelKeyResponderTest.mm",
+    "framework/Source/FlutterCompositorTest.mm",
+    "framework/Source/FlutterEmbedderExternalTextureTest.mm",
+    "framework/Source/FlutterEmbedderKeyResponderTest.mm",
     "framework/Source/FlutterEngineTest.mm",
     "framework/Source/FlutterEngineTestUtils.h",
     "framework/Source/FlutterEngineTestUtils.mm",
-    "framework/Source/FlutterKeyboardManagerUnittests.mm",
+    "framework/Source/FlutterKeyboardManagerTest.mm",
     "framework/Source/FlutterMenuPluginTest.mm",
     "framework/Source/FlutterPlatformNodeDelegateMacTest.mm",
     "framework/Source/FlutterPlatformViewControllerTest.mm",
@@ -183,7 +183,7 @@ executable("flutter_desktop_darwin_unittests") {
     "framework/Source/FlutterViewControllerTest.mm",
     "framework/Source/FlutterViewControllerTestUtils.h",
     "framework/Source/FlutterViewControllerTestUtils.mm",
-    "framework/Source/FlutterViewEngineProviderUnitTests.mm",
+    "framework/Source/FlutterViewEngineProviderTest.mm",
     "framework/Source/TestFlutterPlatformView.h",
     "framework/Source/TestFlutterPlatformView.mm",
   ]