IconicsMenuInflatUtil is not compatible with app bundles
- Used library version: `3.0.3`
- Used support library version `27.1.1`
- Used gradle build tools version: `28-rc-2`
- Used tooling / Android Studio version: `3.2.0-alpha15`
- Other used libraries, potential conflicting libraries: Irrelevant

I just tried to build an [app bundle](https://developer.android.com/guide/app-bundle/) from my app and stumbled upon the attached crash. This seems to happen, because the tool repackages the resource to not be in the expected `@<idNumber>` format but to still contain the actual reference (in my case `@+id/filter`).

@MFlisar maybe you can take a look since you initially implemented this?
Thanks in advance!

Problematic item in my menu:

```xml
<item
    android:id="@+id/filter"
    android:title="@string/action_filter"
    app:ico_color="@android:color/white"
    app:ico_icon="cmd_filter_variant"
    app:ico_padding="2dp"
    app:ico_size="24dp"
    app:showAsAction="ifRoom">
```

Stacktrace:

```ruby
java.lang.NumberFormatException: For input string: "+id/filter"
        at java.lang.Integer.parseInt(Integer.java:608)
        at java.lang.Integer.parseInt(Integer.java:643)
        at com.mikepenz.iconics.IconicsMenuInflaterUtil.parseMenu(SourceFile:115)
        at com.mikepenz.iconics.IconicsMenuInflaterUtil.inflate(SourceFile:70)
        ...
```