Require TEST_INPUT_METHOD instead in IMM#addVirtualStylusIdForTestSession()

This is a follow up CL to our previous CL [1], which introduced an @TestApi

  InputMethodManager#addVirtualStylusIdForTestSession(),

which internally requires INJECT_EVENTS permission.

Now that TEST_INPUT_METHOD is also available [2], let's require it
instead of INJECT_EVENTS for better consistency with other test APIs
defined in InputMethodManager.

This CL also add @RequiresPermission(TEST_INPUT_METHOD) to

  InputMethodManager#addVirtualStylusIdForTestSession()

to make it clear that it's guarded with the permission.

 [1]: I7399c0a56c04f024d65c16d459818cc2c5cdbc7f
      d96ef57bc4
 [2]: Ie79a3e9d41ce22605ae083594d639c37d08b7def
      b869c78380

Bug: 256239860
Test: atest CtsInputMethodTestCases:StylusHandwritingTest
Change-Id: Icdbb4ade2bd4b5066984e209efcf0ca93bfa08ca

core/api/test-current.txt

@@ -3157,7 +3157,7 @@ package android.view.inputmethod {
   }
 
   public final class InputMethodManager {
-    method public void addVirtualStylusIdForTestSession();
+    method @RequiresPermission(android.Manifest.permission.TEST_INPUT_METHOD) public void addVirtualStylusIdForTestSession();
     method public int getDisplayId();
     method @NonNull @RequiresPermission(android.Manifest.permission.INTERACT_ACROSS_USERS_FULL) public java.util.List<android.view.inputmethod.InputMethodInfo> getInputMethodListAsUser(int);
     method public boolean hasActiveInputConnection(@Nullable android.view.View);

core/java/android/view/inputmethod/IInputMethodManagerGlobalInvoker.java

@@ -489,6 +489,7 @@ final class IInputMethodManagerGlobalInvoker {
     }
 
     @AnyThread
+    @RequiresPermission(Manifest.permission.TEST_INPUT_METHOD)
     static void addVirtualStylusIdForTestSession(IInputMethodClient client) {
         final IInputMethodManager service = getService();
         if (service == null) {

core/java/android/view/inputmethod/InputMethodManager.java

@@ -2590,6 +2590,7 @@ public final class InputMethodManager {
      * @hide
      */
     @TestApi
+    @RequiresPermission(Manifest.permission.TEST_INPUT_METHOD)
     public void addVirtualStylusIdForTestSession() {
         synchronized (mH) {
             IInputMethodManagerGlobalInvoker.addVirtualStylusIdForTestSession(mClient);

core/java/com/android/internal/view/IInputMethodManager.aidl

@@ -147,9 +147,9 @@ interface IInputMethodManager {
     boolean isStylusHandwritingAvailableAsUser(int userId);
 
     /** add virtual stylus id for test Stylus handwriting session **/
-    @EnforcePermission("INJECT_EVENTS")
+    @EnforcePermission("TEST_INPUT_METHOD")
     @JavaPassthrough(annotation="@android.annotation.RequiresPermission(value = "
-            + "android.Manifest.permission.INJECT_EVENTS)")
+            + "android.Manifest.permission.TEST_INPUT_METHOD)")
     void addVirtualStylusIdForTestSession(in IInputMethodClient client);
 
     /** Set a stylus idle-timeout after which handwriting {@code InkWindow} will be removed. */

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

@@ -4382,7 +4382,7 @@ public final class InputMethodManagerService extends IInputMethodManager.Stub
      * a stylus deviceId is not already registered on device.
      */
     @BinderThread
-    @EnforcePermission(Manifest.permission.INJECT_EVENTS)
+    @EnforcePermission(Manifest.permission.TEST_INPUT_METHOD)
     @Override
     public void addVirtualStylusIdForTestSession(IInputMethodClient client) {
         int uid = Binder.getCallingUid();