去掉开机提示“android is starting”的提示框

在 frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java 中

屏蔽如下代码：

if (doTrim) {
    /*if (!isFirstBoot()) {
        try {
            ActivityManagerNative.getDefault().showBootMessage(
                    mContext.getResources().getString(
                            R.string.android_upgrading_fstrim), true);
        } catch (RemoteException e) {
        }
    }

   */
    ms.runMaintenance();
}