[Android] ignore .idea/navEditor.xml (#3012)

Android.gitignore

@@ -45,6 +45,8 @@ captures/
 # Android Studio 3 in .gitignore file.
 .idea/caches/build_file_checksums.ser
 .idea/modules.xml
+# Comment next line if keeping position of elements in Navigation Editor is relevant for you
+.idea/navEditor.xml
 
 # Keystore files
 # Uncomment the following lines if you do not want to check your keystore files in.