build with firebase if firebase flavor is selected

Change-Id: I1117f712e4345c218e54576caa515a9076d0252e
diff --git a/ring-android/build.gradle b/ring-android/build.gradle
index 78a0177..3b1cc76 100644
--- a/ring-android/build.gradle
+++ b/ring-android/build.gradle
@@ -1,7 +1,7 @@
 buildscript {
     repositories {
-        jcenter()
         google()
+        jcenter()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.1.2'
@@ -10,8 +10,8 @@
 }
 allprojects {
     repositories {
-        jcenter()
         google()
+        jcenter()
     }
 }