iOS: Rename FlutterPlatformViews_Internal.mm (#56816)

Objective-C files should be named to match their header, in this case, //flutter/shell/platform/darwin/ios/framework/Headers/FlutterPlatformViews.h.

When private API is required, we often create a header named FlutterFoo_Internal.h, but the implementation file is always just FlutterFoo.mm. This brings FlutterPlatformViews back into line with convention.

No test changes since this is just a file rename.

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

Author: cbracken

ci/licenses_golden/licenses_flutter

@@ -44563,11 +44563,11 @@ ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterOverl
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformPluginTest.mm + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsController.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsController.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsTest.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPluginAppLifeCycleDelegate.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPluginAppLifeCycleDelegateTest.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPluginAppLifeCycleDelegate_internal.h + ../../../flutter/LICENSE
@@ -47499,11 +47499,11 @@ FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterOverlay
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformPluginTest.mm
+FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsController.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsController.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsTest.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.h
-FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPluginAppLifeCycleDelegate.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPluginAppLifeCycleDelegateTest.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPluginAppLifeCycleDelegate_internal.h

shell/platform/darwin/ios/BUILD.gn

@@ -79,10 +79,10 @@ source_set("flutter_framework_source") {
     "framework/Source/FlutterOverlayView.mm",
     "framework/Source/FlutterPlatformPlugin.h",
     "framework/Source/FlutterPlatformPlugin.mm",
+    "framework/Source/FlutterPlatformViews.mm",
     "framework/Source/FlutterPlatformViewsController.h",
     "framework/Source/FlutterPlatformViewsController.mm",
     "framework/Source/FlutterPlatformViews_Internal.h",
-    "framework/Source/FlutterPlatformViews_Internal.mm",
     "framework/Source/FlutterPluginAppLifeCycleDelegate.mm",
     "framework/Source/FlutterRestorationPlugin.h",
     "framework/Source/FlutterRestorationPlugin.mm",