Make InputMethodInfo#showInInputMethodPicker public.

Allows custom Input Method Pickers to exclude relevant IMEs, like the
system picker does now.

Fix: 184890628
Test: atest InputMethodInfoTest InputMethodManagerTest
Change-Id: I20033de2f6679ed8cd538de66e157f737792d847

core/api/current.txt

@@ -51977,6 +51977,7 @@ package android.view.inputmethod {
     method public int getSubtypeCount();
     method public android.graphics.drawable.Drawable loadIcon(android.content.pm.PackageManager);
     method public CharSequence loadLabel(android.content.pm.PackageManager);
+    method public boolean shouldShowInInputMethodPicker();
     method public boolean suppressesSpellChecker();
     method public void writeToParcel(android.os.Parcel, int);
     field @NonNull public static final android.os.Parcelable.Creator<android.view.inputmethod.InputMethodInfo> CREATOR;

core/java/android/view/inputmethod/InputMethodInfo.java

@@ -638,10 +638,11 @@ public final class InputMethodInfo implements Parcelable {
     }
 
     /**
-     * Return {@code true} if this input method should be shown in the IME picker.
-     * @hide
+     * Returns {@code true} if this input method should be shown in menus for selecting an Input
+     * Method, such as the system Input Method Picker. This is {@code false} if the IME is intended
+     * to be accessed programmatically.
      */
-    public boolean showInInputMethodPicker() {
+    public boolean shouldShowInInputMethodPicker() {
         return mShowInInputMethodPicker;
     }
 

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

@@ -196,7 +196,7 @@ final class InputMethodSubtypeSwitchingController {
             final int numImes = imis.size();
             for (int i = 0; i < numImes; ++i) {
                 final InputMethodInfo imi = imis.get(i);
-                if (forImeMenu && !imi.showInInputMethodPicker()) {
+                if (forImeMenu && !imi.shouldShowInInputMethodPicker()) {
                     continue;
                 }
                 final List<InputMethodSubtype> explicitlyOrImplicitlyEnabledSubtypeList =