update url for apk-splits user-guide (facebook#24253)

Summary:
Changed apk-splits user-guide url.

[ANDROID] [CHANGED] - Apk tools url.
Pull Request resolved: facebook#24253

Differential Revision: D14724834

Pulled By: cpojer

fbshipit-source-id: 8e9e21ebdcb0d585f1f262640e259ccf71112adb

Author: a-c-sreedhar-reddy

template/android/app/build.gradle

@@ -140,7 +140,7 @@ android {
     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
+            // https://developer.android.com/studio/build/configure-apk-splits.html
             def versionCodes = ["armeabi-v7a": 1, "x86": 2, "arm64-v8a": 3, "x86_64": 4]
             def abi = output.getFilter(OutputFile.ABI)
             if (abi != null) {  // null for the universal-debug, universal-release variants