Change app id based on current git branch

This enables to install multiple builds from different branches at once

app/src/main/res/values/strings.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <string name="app_name" translatable="false">NewPipe</string>
     <string name="main_bg_subtitle">Tap \"Search\" to get started</string>
     <string name="view_count_text">%1$s views</string>
     <string name="upload_date_text">Published on %1$s</string>