App is crashing after upgrading gradle "gradle-4.1-all.zip" - react-native

Question

I have upgraded my "gradle-wrapper.properties" to use "gradle-4.1-all.zip". When I am trying to build it's successful but app is crashing in both Genymotion as well as in device.
I tried cleaning my node modules but still it's not working.
Versions - "react-native": "0.47.1", "react": "16.0.0-alpha.12"
android {
compileSdkVersion 23
buildToolsVersion "23.0.1"
defaultConfig {
applicationId "com.mjb"
minSdkVersion 16
targetSdkVersion 22
versionCode 1
versionName "1.0"
ndk {
abiFilters "armeabi-v7a", "x86"
}
}
splits {
abi {
reset()
enable enableSeparateBuildPerCPUArchitecture
universalApk false // If true, also generate a universal APK
include "armeabi-v7a", "x86"
}
}
buildTypes {
release {
minifyEnabled enableProguardInReleaseBuilds
proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
}
}
// applicationVariants are e.g. debug, release
applicationVariants.all { variant ->
variant.outputs.each { output ->
// For each separate APK per architecture, set a unique version code as described here:
// http://tools.android.com/tech-docs/new-build-system/user-guide/apk-splits
def versionCodes = ["armeabi-v7a":1, "x86":2]
def abi = output.getFilter(OutputFile.ABI)
if (abi != null) { // null for the universal-debug, universal-release variants
output.versionCodeOverride =
versionCodes.get(abi) * 1048576 + defaultConfig.versionCode
}
}
}
}
Here is the root build.gradle
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.0.1'
classpath 'com.google.gms:google-services:3.0.0'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}