Fix react native version in android build.gradel file

android/build.gradle

 
 dependencies {
     implementation "com.android.support:support-v4:${safeExtGet('supportLibVersion', '27.+')}"
-    api 'com.facebook.react:react-native:+'
+    api "com.facebook.react:react-native:${rootProject.ext.reactNative}"
 }