问题:设置默认输入法为第三方输入法，切换语言后输入法变为其他输入法
原因（Android 11）:
frameworks/base/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
private void resetDefaultImeLocked(Context context) {// Do not reset the default (current) IME when it is a 3rd-party IMEif (mCurMethodId != null && !mMethodMap.get(mCurMethodId).isSystem()) {return;}final List<InputMethodInfo> suitableImes = InputMethodUtils.getDefaultEnabledImes(context, mSettings.getEnabledInputMethodListLocked());if (suitableImes.isEmpty()) {Slog.i(TAG, "No default found");return;}final InputMethodInfo defIm = suitableImes.get(0);if (DEBUG) {Slog.i(TAG, "Default found, using " + defIm.getId());}setSelectedInputMethodAndSubtypeLocked(defIm, NOT_A_SUBTYPE_ID, false);}
由于切语言后，非系统输入法不会被设置，删除以下代码
if (mCurMethodId != null && !mMethodMap.get(mCurMethodId).isSystem()) {return;}
/nei504293736/article/details/51599733（android 切换系统语言，输入法也随之切换）
