Update ReactAndroid build script to support gradle 2.3.0

[venik]

Motivation

We updated to Gradle 2.3.0 and our app's build failed. Our app doesn't provide "repositoryUrl" which is intended to be an optional gradle property. However, Gradle 2.3.0 blows up on findProperty('repositoryUrl') when "repositoryUrl" isn't provided:

* What went wrong:
A problem occurred configuring project ':ContextMenuAndroid'.
> Could not resolve all dependencies for configuration ':ContextMenuAndroid:_debugPublish'.
   > A problem occurred configuring project ':ReactAndroid'.
      > Could not get unknown property 'repositoryUrl' for project ':ReactAndroid' of type org.gradle.api.Project.

To fix this, we now use "project.hasProperty('repositoryUrl')" to safely detect the presence of the optional "repositoryUrl" property.

Test Plan

Since I cannot check it with your build environment, I've created a small demo to show that "project.hasProperty" properly detects the presence of the gradle property "repositoryUrl". I edited "getRepositoryUrl" to throw an exception if "repositoryUrl" is set:

def getRepositoryUrl() {
    if (project.hasProperty('repositoryUrl')) throw new GradleException(property('repositoryUrl'))

    return project.hasProperty('repositoryUrl') ? property('repositoryUrl') : 'https://oss.sonatype.org/service/local/staging/deploy/maven2/'
}

Then I ran gradle with "repositoryUrl" set like this (passing the property):

./gradlew -PrepositoryUrl=blah assembleDebug

As expected, it detected that "repositoryUrl" was set and threw an exception:

* What went wrong:
A problem occurred configuring project ':ContextMenuAndroid'.
> Could not resolve all dependencies for configuration ':ContextMenuAndroid:_debugPublish'.
   > A problem occurred configuring project ':ReactAndroid'.
      > blah

Related PRs

The same issue has been reported before - #14811, #14810

Release Notes

Minor changes in the Android build script

[ide]

LGTM

@facebook-github-bot shipit

[facebook-github-bot]

Something went wrong executing that command, @hramos could you take a look?

[facebook-github-bot]

@ide is landing this pull request. If you are a Facebook employee, you can view this diff on Phabricator.