Ionic :app:processDebugGoogleServices (Version conflict) - ionic-framework

Question

I installed push plugin on ionic app and got this build fail
Found firebase-messaging:11.6.2, but version 11.0.4 is needed for the google-services plugin.
:app:processDebugGoogleServices FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:processDebugGoogleServices'.
>
Please fix the version conflict either by updating the version of the google-services plugin (information about the latest version is available at https://bintray.com/android/android-tools/com.google.gms.google-services/) or updating the version of com.google.android.gms to 11.0.4.
my build.gradle (module:app)
dependencies {
implementation fileTree(dir: 'libs', include: '*.jar')
// SUB-PROJECT DEPENDENCIES START
implementation(project(path: ":CordovaLib"))
compile "com.facebook.android:facebook-android-sdk:4.+"
compile "com.google.android.gms:play-services-base:11.0.4"
compile "com.google.android.gms:play-services-ads:11.0.4"
compile "com.android.support:support-v13:23+"
compile "com.android.support:support-v13:27.+"
compile "me.leolin:ShortcutBadger:1.1.17#aar"
compile "com.google.firebase:firebase-messaging:11.6.2"
// SUB-PROJECT DEPENDENCIES END
}

Answer 1

Declare the FCM version in config.xml like this:
<plugin name="phonegap-plugin-push" spec="^2.1.3">
<variable name="FCM_VERSION" value="11.6.2" />
</plugin>
If that doesn't work, some of the steps of I use to solve pesky Ionic build problems are:
rm -rf node_modules
ionic cordova platform rm
rm -rf platforms
rm -rf plugins
npm install
ionic cordova platform add