Inline IMMS#startInputOrWindowGainedFocusInternal

This is a follow up CL to my previous CL [1], which aimed to be a
logical revert of changes mentioned in the commit message.

One thing that CL forgot to handle was

  InputMethodManagerService#startInputOrWindowGainedFocusInternal,

which was mentioned in one of our previous CLs [2].

This CL inlines that method again for simplicity.

This is a mechanical refactoring.  There should be no behavior change.

 [1]: If16ac0de536d9089eb04f6e07b1ee47378124658
      662b48b72d
 [2]: Ic584203c1221fbae17f5e2d8f09e3992df061646
      5e2d9f271d

Bug: 234882948
Test: presubmit
Change-Id: I7c775245882815483f29acfd83f53b08a40d07ed

services/core/java/com/android/server/inputmethod/InputMethodManagerService.java

@@ -3576,21 +3576,6 @@ public final class InputMethodManagerService extends IInputMethodManager.Stub
             IRemoteAccessibilityInputConnection remoteAccessibilityInputConnection,
             int unverifiedTargetSdkVersion,
             @NonNull ImeOnBackInvokedDispatcher imeDispatcher) {
-        return startInputOrWindowGainedFocusInternal(startInputReason, client, windowToken,
-                startInputFlags, softInputMode, windowFlags, editorInfo, inputConnection,
-                remoteAccessibilityInputConnection, unverifiedTargetSdkVersion,
-                imeDispatcher);
-    }
-
-    @NonNull
-    private InputBindResult startInputOrWindowGainedFocusInternal(
-            @StartInputReason int startInputReason, IInputMethodClient client, IBinder windowToken,
-            @StartInputFlags int startInputFlags, @SoftInputModeFlags int softInputMode,
-            int windowFlags, @Nullable EditorInfo editorInfo,
-            @Nullable IRemoteInputConnection inputConnection,
-            @Nullable IRemoteAccessibilityInputConnection remoteAccessibilityInputConnection,
-            int unverifiedTargetSdkVersion,
-            @NonNull ImeOnBackInvokedDispatcher imeDispatcher) {
         if (windowToken == null) {
             Slog.e(TAG, "windowToken cannot be null.");
             return InputBindResult.NULL;