Deprecate InputMethod#SHOW_FORCED

As InputMethodManager#SHOW_FORCED was deprecated in T,
we should keep both flags consistently deprecated.

Test: n/a
Bug: 289210045
Change-Id: I399484cb43bd60e3e8904358940273353a839b8a

core/api/current.txt

@@ -55765,7 +55765,7 @@ package android.view.inputmethod {
     field public static final String SERVICE_INTERFACE = "android.view.InputMethod";
     field public static final String SERVICE_META_DATA = "android.view.im";
     field public static final int SHOW_EXPLICIT = 1; // 0x1
-    field public static final int SHOW_FORCED = 2; // 0x2
+    field @Deprecated public static final int SHOW_FORCED = 2; // 0x2
   }
 
   public static interface InputMethod.SessionCallback {

core/java/android/view/inputmethod/InputMethod.java

@@ -282,7 +282,11 @@ public interface InputMethod {
      * Flag for {@link #showSoftInput}: this show has been forced to
      * happen by the user.  If set, the input method should remain visible
      * until deliberated dismissed by the user in its UI.
+     *
+     * @deprecated {@link InputMethodManager#SHOW_FORCED} is deprecated and
+     * should no longer be used by apps. IMEs likewise should no longer react to this flag.
      */
+    @Deprecated
     public static final int SHOW_FORCED = 0x00002;
 
     /**

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

@@ -2018,7 +2018,7 @@ public final class InputMethodManager {
      *
      * @deprecated Use {@link #showSoftInput} without this flag instead. Using this flag can lead
      * to the soft input remaining visible even when the calling application is closed. The
-     * use of this flag can make the soft input remains visible globally. Starting in
+     * use of this flag can make the soft input remain visible globally. Starting in
      * {@link Build.VERSION_CODES#TIRAMISU Android T}, this flag only has an effect while the
      * caller is currently focused.
      */