Update build.gradle to use local version of react-native

 - This change is taken from the build.gradle created after running this command: npx @react-native-community/bob create react-native-awesome-module
 - Info taken from here: https://reactnative.dev/docs/native-modules-setup

Author: Fran Montiel

android/build.gradle

@@ -30,6 +30,71 @@ android {
 repositories {
   jcenter()
   google()
+
+  def found = false
+  def defaultDir = null
+  def androidSourcesName = 'React Native sources'
+
+  if (rootProject.ext.has('reactNativeAndroidRoot')) {
+    defaultDir = rootProject.ext.get('reactNativeAndroidRoot')
+  } else {
+    defaultDir = new File(
+        projectDir,
+        '/../../../node_modules/react-native/android'
+    )
+  }
+
+  if (defaultDir.exists()) {
+    maven {
+      url defaultDir.toString()
+      name androidSourcesName
+    }
+
+    logger.info(":${project.name}:reactNativeAndroidRoot ${defaultDir.canonicalPath}")
+    found = true
+  } else {
+    def parentDir = rootProject.projectDir
+
+    1.upto(5, {
+      if (found) return true
+      parentDir = parentDir.parentFile
+
+      def androidSourcesDir = new File(
+          parentDir,
+          'node_modules/react-native'
+      )
+
+      def androidPrebuiltBinaryDir = new File(
+          parentDir,
+          'node_modules/react-native/android'
+      )
+
+      if (androidPrebuiltBinaryDir.exists()) {
+        maven {
+          url androidPrebuiltBinaryDir.toString()
+          name androidSourcesName
+        }
+
+        logger.info(":${project.name}:reactNativeAndroidRoot ${androidPrebuiltBinaryDir.canonicalPath}")
+        found = true
+      } else if (androidSourcesDir.exists()) {
+        maven {
+          url androidSourcesDir.toString()
+          name androidSourcesName
+        }
+
+        logger.info(":${project.name}:reactNativeAndroidRoot ${androidSourcesDir.canonicalPath}")
+        found = true
+      }
+    })
+  }
+
+  if (!found) {
+    throw new GradleException(
+        "${project.name}: unable to locate React Native android sources. " +
+            "Ensure you have you installed React Native as a dependency in your project and try again."
+    )
+  }
 }
 
 dependencies {