chore: ensure android aar build instead of a manifest file before publishing to npm

Author: DimitarTachev

.gitignore

@@ -31,3 +31,5 @@ npm-debug.log
 node_modules
 !Gruntfile.js
 .d.ts
+
+platforms/android/nativescript_unit_test_runner.aar

.npmignore

@@ -14,3 +14,5 @@ tscommand.tmp.txt
 *.ts
 *.js.map
 definitions
+platforms/android/*
+!platforms/android/*.aar