Update RN and Viro. iOS build working

mobile/android/app/build.gradle

@@ -173,3 +173,12 @@ task copyDownloadableDepsToLibs(type: Copy) {
     from configurations.compile
     into 'libs'
 }
+
+repositories {
+    google()
+}
+buildscript {
+    repositories {
+        google()
+    }
+}

mobile/android/build.gradle

@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.2.3'
+        classpath 'com.android.tools.build:gradle:3.1.2'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files