Make fresco a stand-alone gradle project (#548)

Summary:
Pull Request resolved: https://github.com/facebook/flipper/pull/548

First project to pull out of the "fat distribution" we currently have.
Still needs setup for Maven and registration in Bintray.

Reviewed By: jknoxville

Differential Revision: D17395660

fbshipit-source-id: 6244495a2e25d705dd930ef87c7e5e1f038eb921

android/tutorial/build.gradle

@@ -45,6 +45,7 @@ dependencies {
     // For simplicity, we use Flipper for both debug and release builds here.
     // Check out the "sample" app to see how to separate your build flavors.
     implementation project(':android')
+    implementation project(':fresco-plugin')
     implementation deps.soloader
 
     // Litho