New release process: simplify installArchives

Summary:
Output the Android artifacts in the new location so we can simply
do `./gradlew :ReactAndroid:installArchives` and `npm publish`.

**Test Plan**

Same as test plan of 702f999b05 without having to manually move the artifacts.

public

Reviewed By: bestander

Differential Revision: D2916664

fb-gh-sync-id: 27dcc711b3055a5a6c554ed1e69cf4a64add849c
shipit-source-id: 27dcc711b3055a5a6c554ed1e69cf4a64add849c

ReactAndroid/release.gradle

@@ -117,12 +117,8 @@ afterEvaluate { project ->
     task installArchives(type: Upload) {
         configuration = configurations.archives
         repositories.mavenDeployer {
-            beforeDeployment {
-                MavenDeployment deployment -> signing.signPom(deployment)
-            }
-
-            repository url: "file://${System.properties['user.home']}/.m2/repository"
-            configureReactNativePom pom
+            // Deploy to react-native/android, ready to publish to npm
+            repository url: "file://${projectDir}/../android"
         }
     }
 }