Firebase Remote Config NullPointer
<p>I'm getting the following error:</p>

<pre><code>09-04 10:45:50.429 4841-4869 E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #3
    Process: com.xxx.xxx, PID: 4841
       java.lang.NullPointerException: Attempt to invoke interface method 'java.util.Set java.util.Map.keySet()' on a null object reference
           at com.google.android.gms.internal.zzalt.zza(Unknown Source)
           at com.google.android.gms.internal.zzalt.run(Unknown Source)
           at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
           at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
           at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
           at java.lang.Thread.run(Thread.java:818)
</code></pre>

<p>This error only gives me when I added Remote Config firebase code as they explain in the project code example.</p>

<p>This is my gradle:</p>

<pre><code>apply plugin: 'com.android.application'

android {
    compileSdkVersion "Google Inc.:Google APIs:23"
    buildToolsVersion "23.0.3"
    useLibrary  'org.apache.http.legacy'

    defaultConfig {
        applicationId "com.batriks.getblue"
        minSdkVersion 15
        targetSdkVersion 20
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }
}

dependencies {
    compile project(':slidingMenu')
    compile project(':flip3DViewTransition')
    compile project(':facebookSDK')
    compile files('libs/universal-image-loader-1.9.2.jar')
    compile 'com.google.android.gms:play-services-location:9.4.0'
    compile 'com.google.android.gms:play-services:9.4.0'
//    compile 'com.google.android.gms:play-services-ads:9.2.0'
    compile 'com.google.firebase:firebase-core:9.0.2'
    compile 'com.google.firebase:firebase-config:9.0.2'
    compile 'com.android.support:support-v4:23.0.1'
    compile 'com.android.support:appcompat-v7:23.0.1'
    //compile 'com.google.android.gms:play-services:7.8.0'
}

apply plugin: 'com.google.gms.google-services'
</code></pre>

<p>Top level gradle:</p>

<pre><code>// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.1.3'
        classpath 'com.google.gms:google-services:3.0.0'
    }
}

allprojects {
    repositories {
        jcenter()
    }
}
</code></pre>

<p>I have added google-services.json also, and  proved several libs configs but nothing appears to work.</p>

<p>How can I solve this problem?</p>