Update firebase version

app/build.gradle

@@ -45,9 +45,6 @@ android {
         }
         release {
             minifyEnabled true
-            firebaseCrashlytics {
-                mappingFileUploadEnabled false
-            }
 
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
             applicationVariants.all { variant ->
@@ -124,7 +121,7 @@ dependencies {
     implementation 'com.android.billingclient:billing:1.2.2'
 
     // Firebase
-    implementation 'com.google.firebase:firebase-core:17.4.2'
+    implementation 'com.google.firebase:firebase-core:17.4.4'
 
     // Crashlytics
     implementation 'com.crashlytics.sdk.android:crashlytics:2.10.1'